Overdose
Symptoms of overdosage may include drowsiness, disorientation and extrapyramidal reactions.
Anticholinergic or antiparkinson drugs or antihistamines with anticholinergic properties may be helpful
in controlling the extrapyramidal reactions. Symptoms are self-limiting and usually disappear within 24
hours.
Hemodialysis removes relatively little metoclopramide, probably because of the small amount of the
drug in blood relative to tissues. Similarly, continuous ambulatory peritoneal dialysis does not remove
significant amounts of drug. It is unlikely that dosage would need to be adjusted to compensate for
losses through dialysis. Dialysis is not likely to be an effective method of drug removal in overdose
situations.
Unintentional overdose due to misadministration has been reported in infants and children with the use of
metoclopramide oral solution. While there was no consistent pattern to the reports associated with these
overdoses, events included seizures, extrapyramidal reactions, and lethargy.
Methemoglobinemia has occurred in premature and full-term neonates who were given overdoses of
metoclopramide (1 to 4 mg/kg/day orally, intramuscularly or intravenously for 1 to 3 or more days).
Methemoglobinemia can be reversed by the intravenous administration of methylene blue. However,
methylene blue may cause hemolytic anemia in patients with G6PD deficiency, which may be fatal (see PRECAUTIONS – Other Special Populations).
Contraindications
Metoclopramide should not be used whenever stimulation of gastrointestinal motility might be
dangerous, e.g., in the presence of gastrointestinal hemorrhage, mechanical obstruction, or perforation.
Metoclopramide is contraindicated in patients with pheochromocytoma because the drug may cause a
hypertensive crisis, probably due to release of catecholamines from the tumor. Such hypertensive
crises may be controlled by phentolamine.
Metoclopramide is contraindicated in patients with known sensitivity or intolerance to the drug.
Metoclopramide should not be used in epileptics or patients receiving other drugs which are likely to
cause extrapyramidal reactions, since the frequency and severity of seizures or extrapyramidal
reactions may be increased.
Undesirable effects
In general, the incidence of adverse reactions correlates with the dose and duration of metoclopramide
administration. The following reactions have been reported, although in most instances, data do not
permit an estimate of frequency:
CNS Effects
Restlessness, drowsiness, fatigue, and lassitude occur in approximately 10% of patients receiving the
most commonly prescribed dosage of 10 mg q.i.d. (see PRECAUTIONS). Insomnia, headache,
confusion, dizziness, or mental depression with suicidal ideation (see WARNINGS) occur less
frequently. The incidence of drowsiness is greater at higher doses. There are isolated reports of
convulsive seizures without clear-cut relationship to metoclopramide. Rarely, hallucinations have been
reported.
Extrapyramidal Reactions (EPS)
Acute dystonic reactions, the most common type of EPS associated with metoclopramide, occur in
approximately 0.2% of patients (1 in 500) treated with 30 to 40 mg of metoclopramide per day.
Symptoms include involuntary movements of limbs, facial grimacing, torticollis, oculogyric crisis,
rhythmic protrusion of tongue, bulbar type of speech, trismus, opisthotonus (tetanus-like reactions), and,
rarely, stridor and dyspnea possibly due to laryngospasm; ordinarily these symptoms are readily
reversed by diphenhydramine (see WARNINGS).
Parkinsonian-like symptoms may include bradykinesia, tremor, cogwheel rigidity, mask-like facies (see WARNINGS).
Tardive dyskinesia most frequently is characterized by involuntary movements of the tongue, face,
mouth, or jaw, and sometimes by involuntary movements of the trunk and/or extremities; movements may
be choreoathetotic in appearance (see WARNINGS).
Motor restlessness (akathisia) may consist of feelings of anxiety, agitation, jitteriness, and insomnia, as
well as inability to sit still, pacing, foot tapping. These symptoms may disappear spontaneously or
respond to a reduction in dosage.
Neuroleptic Malignant Syndrome
Rare occurrences of neuroleptic malignant syndrome (NMS) have been reported. This potentially fatal
syndrome is comprised of the symptom complex of hyperthermia, altered consciousness, muscular
rigidity, and autonomic dysfunction (see WARNINGS).
Endocrine Disturbances
Galactorrhea, amenorrhea, gynecomastia, impotence secondary to hyperprolactinemia (see PRECAUTIONS). Fluid retention secondary to transient elevation of aldosterone (see CLINICAL PHARMACOLOGY).
Cardiovascular
Hypotension, hypertension, supraventricular tachycardia, bradycardia, fluid retention, acute congestive
heart failure and possible AV block (see CONTRAINDICATIONS and PRECAUTIONS).
Gastrointestinal
Nausea and bowel disturbances, primarily diarrhea.
Hepatic
Rarely, cases of hepatotoxicity, characterized by such findings as jaundice and altered liver function
tests, when metoclopramide was administered with other drugs with known hepatotoxic potential.
Renal
Urinary frequency and incontinence.
Hematologic
A few cases of neutropenia, leukopenia, or agranulocytosis, generally without clear-cut relationship to
metoclopramide. Methemoglobinemia, in adults and especially with overdosage in neonates (see OVERDOSE). Sulfhemoglobinemia in adults.
Allergic Reactions
A few cases of rash, urticaria, or bronchospasm, especially in patients with a history of asthma. Rarely,
angioneurotic edema, including glossal or laryngeal edema.
Miscellaneous
Visual disturbances. Porphyria.
Pharmacokinetic properties
).
In addition, neonates have reduced levels of NADH-cytochrome b5 reductase which, in combination
with the aforementioned pharmacokinetic factors, make neonates more susceptible to
methemoglobinemia (see
OVERDOSE).
The safety profile of metoclopramide in adults cannot be extrapolated to pediatric patients. Dystonias
and other extrapyramidal reactions associated with metoclopramide are more common in the pediatric
population than in adults. (See WARNINGS and ADVERSE REACTIONS - Extrapyramidal
Reactions.)
Geriatric Use
Clinical studies of reglan® did not include sufficient numbers of subjects aged 65 and over to determine
whether elderly subjects respond differently from younger subjects.
The risk of developing parkinsonian-like side effects increases with ascending dose. Geriatric patients
should receive the lowest dose of reglan® that is effective. If parkinsonian-like symptoms develop in a
geriatric patient receiving reglan® , reglan® should generally be discontinued before initiating any
specific anti-parkinsonian agents (see WARNINGS and DOSAGE AND ADMINISTRATION – For the Relief of Symptomatic Gas troes ophageal Reflux).
The elderly may be at greater risk for tardive dyskinesia (see WARNINGS – Tardive Dys kinesia).
Sedation has been reported in reglan® users. Sedation may cause confusion and manifest as oversedation
in the elderly (see CLINICAL PHARMACOLOGY, PRECAUTIONS – Information for
Patients and ADVERSE REACTIONS – CNS Effects).
reglan® is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug
may be greater in patients with impaired renal function (see DOSAGE AND ADMINISTRATION –
Use in Patients with Renal or Hepatic Impairment).
For these reasons, dose selection for an elderly patient should be cautious, usually starting at the low
end of the dosing range, reflecting the greater frequency of decreased renal function, concomitant
disease, or other drug therapy in the elderly (see DOSAGE AND ADMINISTRATION – For the
Relief of Symptomatic Gastroesophageal Reflux and Use in Patients with Renal or Hepatic
Impairment).
Other Special Populations
Patients with NADH-cytochrome b5 reductase deficiency are at an increased risk of developing
methemoglobinemia and/or sulfhemoglobinemia when metoclopramide is administered. In patients with
G6PD deficiency who experience metoclopramide- induced methemoglobinemia, methylene blue
treatment is not recommended (see OVERDOSE).
Overdosage & Contraindications
OVERDOSE
Symptoms of overdosage may include drowsiness, disorientation and extrapyramidal reactions.
Anticholinergic or antiparkinson drugs or antihistamines with anticholinergic properties may be helpful
in controlling the extrapyramidal reactions. Symptoms are self-limiting and usually disappear within 24
hours.
Hemodialysis removes relatively little metoclopramide, probably because of the small amount of the
drug in blood relative to tissues. Similarly, continuous ambulatory peritoneal dialysis does not remove
significant amounts of drug. It is unlikely that dosage would need to be adjusted to compensate for
losses through dialysis. Dialysis is not likely to be an effective method of drug removal in overdose
situations.
Unintentional overdose due to misadministration has been reported in infants and children with the use of
metoclopramide oral solution. While there was no consistent pattern to the reports associated with these
overdoses, events included seizures, extrapyramidal reactions, and lethargy.
Methemoglobinemia has occurred in premature and full-term neonates who were given overdoses of
metoclopramide (1 to 4 mg/kg/day orally, intramuscularly or intravenously for 1 to 3 or more days).
Methemoglobinemia can be reversed by the intravenous administration of methylene blue. However,
methylene blue may cause hemolytic anemia in patients with G6PD deficiency, which may be fatal (see PRECAUTIONS – Other Special Populations).
CONTRAINDICATIONS
Metoclopramide should not be used whenever stimulation of gastrointestinal motility might be
dangerous, e.g., in the presence of gastrointestinal hemorrhage, mechanical obstruction, or perforation.
Metoclopramide is contraindicated in patients with pheochromocytoma because the drug may cause a
hypertensive crisis, probably due to release of catecholamines from the tumor. Such hypertensive
crises may be controlled by phentolamine.
Metoclopramide is contraindicated in patients with known sensitivity or intolerance to the drug.
Metoclopramide should not be used in epileptics or patients receiving other drugs which are likely to
cause extrapyramidal reactions, since the frequency and severity of seizures or extrapyramidal
reactions may be increased.
Clinical Pharmacology
CLINICAL PHARMACOLOGY
Metoclopramide stimulates motility of the upper gastrointestinal tract without stimulating gastric,
biliary, or pancreatic secretions. Its mode of action is unclear. It seems to sensitize tissues to the action
of acetylcholine. The effect of metoclopramide on motility is not dependent on intact vagal innervation,
but it can be abolished by anticholinergic drugs.
Metoclopramide increases the tone and amplitude of gastric (especially antral) contractions, relaxes the
pyloric sphincter and the duodenal bulb, and increases peristalsis of the duodenum and jejunum resulting
in accelerated gastric emptying and intestinal transit. It increases the resting tone of the lower
esophageal sphincter. It has little, if any, effect on the motility of the colon or gallbladder.
In patients with gastroesophageal reflux and low LESP (lower esophageal sphincter pressure), single
oral doses of metoclopramide produce dose-related increases in LESP. Effects begin at about 5 mg and
increase through 20 mg (the largest dose tested). The increase in LESP from a 5 mg dose lasts about 45
minutes and that of 20 mg lasts between 2 and 3 hours. Increased rate of stomach emptying has been
observed with single oral doses of 10 mg.
The antiemetic properties of metoclopramide appear to be a result of its antagonism of central and
peripheral dopamine receptors. Dopamine produces nausea and vomiting by stimulation of the medullary
chemoreceptor trigger zone (CTZ), and metoclopramide blocks stimulation of the CTZ by agents like ldopa
or apomorphine which are known to increase dopamine levels or to possess dopamine-like
effects. Metoclopramide also abolishes the slowing of gastric emptying caused by apomorphine.
Like the phenothiazines and related drugs, which are also dopamine antagonists, metoclopramide
produces sedation and may produce extrapyramidal reactions, although these are comparatively rare
(see WARNINGS). Metoclopramide inhibits the central and peripheral effects of apomorphine, induces
release of prolactin and causes a transient increase in circulating aldosterone levels, which may be
associated with transient fluid retention.
The onset of pharmacological action of metoclopramide is 1 to 3 minutes following an intravenous
dose, 10 to 15 minutes following intramuscular administration, and 30 to 60 minutes following an oral
dose; pharmacological effects persist for 1 to 2 hours.
Pharmacokinetics
Metoclopramide is rapidly and well absorbed. Relative to an intravenous dose of 20 mg, the absolute
oral bioavailability of metoclopramide is 80% ± 15.5% as demonstrated in a crossover study of 18
subjects. Peak plasma concentrations occur at about 1 to 2 hr after a single oral dose. Similar time to
peak is observed after individual doses at steady state.
In a single dose study of 12 subjects, the area under the drug concentration-time curve increases linearly
with doses from 20 to 100 mg. Peak concentrations increase linearly with dose; time to peak
concentrations remains the same; whole body clearance is unchanged; and the elimination rate remains
the same. The average elimination half-life in individuals with normal renal function is 5 to 6 hr. Linear
kinetic processes adequately describe the absorption and elimination of metoclopramide.
Approximately 85% of the radioactivity of an orally administered dose appears in the urine within 72 hr.
Of the 85% eliminated in the urine, about half is present as free or conjugated metoclopramide.
The drug is not extensively bound to plasma proteins (about 30%). The whole body volume of
distribution is high (about 3.5 L/kg) which suggests extensive distribution of drug to the tissues.
Renal impairment affects the clearance of metoclopramide. In a study with patients with varying degrees
of renal impairment, a reduction in creatinine clearance was correlated with a reduction in plasma
clearance, renal clearance, non-renal clearance, and increase in elimination half-life. The kinetics of
metoclopramide in the presence of renal impairment remained linear however. The reduction in
clearance as a result of renal impairment suggests that adjustment downward of maintenance dosage
should be done to avoid drug accumulation.
Adult Pharmacokinetic Data
| Parameter |
Value |
| Vd (L/kg) |
~ 3.5 |
| Plasma Protein Binding |
~ 30% |
| t1/2(hr) |
5 to 6 |
| Oral Bioavailability |
80%±15.5% |
In pediatric patients, the pharmacodynamics of metoclopramide following oral and intravenous
administration are highly variable and a concentration-effect relationship has not been established.
There are insufficient reliable data to conclude whether the pharmacokinetics of metoclopramide in
adults and the pediatric population are similar. Although there are insufficient data to support the
efficacy of metoclopramide in pediatric patients with symptomatic gastroesophageal reflux (GER) or
cancer chemotherapy-related nausea and vomiting, its pharmacokinetics have been studied in these
patient populations.
In an open-label study, six pediatric patients (age range, 3.5 weeks to 5.4 months) with GER received
metoclopramide 0.15 mg/kg oral solution every 6 hours for 10 doses. The mean peak plasma
concentration of metoclopramide after the tenth dose was 2-fold (56.8 μg/L) higher compared to that
observed after the first dose (29 μg/L) indicating drug accumulation with repeated dosing. After the
tenth dose, the mean time to reach peak concentrations (2.2 hr), half-life (4.1 hr), clearance (0.67 L/h/kg),
and volume of distribution (4.4 L/kg) of metoclopramide were similar to those observed after the first
dose. In the youngest patient (age, 3.5 weeks), metoclopramide half-life after the first and the tenth dose
(23.1 and 10.3 hr, respectively) was significantly longer compared to other infants due to reduced
clearance. This may be attributed to immature hepatic and renal systems at birth.
Single intravenous doses of metoclopramide 0.22 to 0.46 mg/kg (mean, 0.35 mg/kg) were administered
over 5 minutes to 9 pediatric cancer patients receiving chemotherapy (mean age, 11.7 years; range, 7 to
14 yr) for prophylaxis of cytotoxic-induced vomiting. The metoclopramide plasma concentrations
extrapolated to time zero ranged from 65 to 395 μg/L (mean, 152 μg/L). The mean elimination half-life,
clearance, and volume of distribution of metoclopramide were 4.4 hr (range, 1.7 to 8.3 hr), 0.56 L/h/kg
(range, 0.12 to 1.20 L/h/kg), and 3.0 L/kg (range, 1.0 to 4.8 L/kg), respectively.
In another study, nine pediatric cancer patients (age range, 1 to 9 yr) received 4 to 5 intravenous
infusions (over 30 minutes) of metoclopramide at a dose of 2 mg/kg to control emesis. After the last
dose, the peak serum concentrations of metoclopramide ranged from 1060 to 5680 μg/L. The mean
elimination half-life, clearance, and volume of distribution of metoclopramide were 4.5 hr (range, 2.0 to
12.5 hr), 0.37 L/h/kg (range, 0.10 to 1.24 L/h/kg), and 1.93 L/kg (range, 0.95 to 5.50 L/kg), respectively.
Date of revision of the text
Dec 2014
Special warnings and precautions for use
WARNINGS
Mental depression has occurred in patients with and without prior history of depression. Symptoms have
ranged from mild to severe and have included suicidal ideation and suicide. Metoclopramide should be
given to patients with a prior history of depression only if the expected benefits outweigh the potential
risks.
Extrapyramidal symptoms, manifested primarily as acute dystonic reactions, occur in approximately 1 in
500 patients treated with the usual adult dosages of 30 to 40 mg/day of metoclopramide. These usually
are seen during the first 24 to 48 hours of treatment with metoclopramide, occur more frequently in
pediatric patients and adult patients less than 30 years of age and are even more frequent at higher doses.
These symptoms may include involuntary movements of limbs and facial grimacing, torticollis,
oculogyric crisis, rhythmic protrusion of tongue, bulbar type of speech, trismus, or dystonic reactions
resembling tetanus. Rarely, dystonic reactions may present as stridor and dyspnea, possibly due to
laryngospasm. If these symptoms should occur, inject 50 mg diphenhydramine hydrochloride
intramuscularly, and they usually will subside. Benztropine mesylate, 1 to 2 mg intramuscularly, may
also be used to reverse these reactions.
Parkinsonian-like symptoms have occurred, more commonly within the first 6 months after beginning
treatment with metoclopramide, but occasionally after longer periods. These symptoms generally
subside within 2 to 3 months following discontinuance of metoclopramide. Patients with preexisting
Parkinson’s disease should be given metoclopramide cautiously, if at all, since such patients may
experience exacerbation of parkinsonian symptoms when taking metoclopramide.
Tardive Dyskinesia
(See BOX WARNING)
Treatment with metoclopramide can cause tardive dyskinesia (TD), a potentially irreversible and
disfiguring disorder characterized by involuntary movements of the face, tongue, or extremities. The
risk of developing tardive dyskinesia increases with the duration of treatment and the total cumulative
dose. An analysis of utilization patterns showed that about 20% of patients who used metoclopramide
took it for longer than 12 weeks. Treatment with metoclopramide for longer than the recommended 12
weeks should be avoided in all but rare cases where therapeutic benefit is thought to outweigh the risk
of developing TD.
Although the risk of developing TD in the general population may be increased among the elderly,
women, and diabetics, it is not possible to predict which patients will develop metoclopramide-induced
TD. Both the risk of developing TD and the likelihood that TD will become irreversible increase with
duration of treatment and total cumulative dose.
Metoclopramide should be discontinued in patients who develop signs or symptoms of TD. There is no
known effective treatment for established cases of TD, although in some patients, TD may remit,
partially or completely, within several weeks to months after metoclopramide is withdrawn.
Metoclopramide itself may suppress, or partially suppress, the signs of TD, thereby masking the
underlying disease process. The effect of this symptomatic suppression upon the long-term course of
TD is unknown. Therefore, metoclopramide should not be used for the symptomatic control of TD.
Neuroleptic Malignant Syndrome (NMS)
There have been rare reports of an uncommon but potentially fatal symptom complex sometimes
referred to as Neuroleptic Malignant Syndrome (NMS) associated with metoclopramide. Clinical
manifestations of NMS include hyperthermia, muscle rigidity, altered consciousness, and evidence of
autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis and cardiac
arrhythmias).
The diagnostic evaluation of patients with this syndrome is complicated. In arriving at a diagnosis, it is
important to identify cases where the clinical presentation includes both serious medical illness (e.g.,
pneumonia, systemic infection, etc.) and untreated or inadequately treated extrapyramidal signs and
symptoms (EPS). Other important considerations in the differential diagnosis include central
anticholinergic toxicity, heat stroke, malignant hyperthermia, drug fever and primary central nervous
system (CNS) pathology.
The management of NMS should include 1) immediate discontinuation of metoclopramide and other
drugs not essential to concurrent therapy, 2) intensive symptomatic treatment and medical monitoring, and
3) treatment of any concomitant serious medical problems for which specific treatments are available.
Bromocriptine and dantrolene sodium have been used in treatment of NMS, but their effectiveness have
not been established (see ADVERSE REACTIONS).
PRECAUTIONS
General
In one study in hypertensive patients, intravenously administered metoclopramide was shown to release
catecholamines; hence, caution should be exercised when metoclopramide is used in patients with
hypertension.
Because metoclopramide produces a transient increase in plasma aldosterone, certain patients,
especially those with cirrhosis or congestive heart failure, may be at risk of developing fluid retention
and volume overload. If these side effects occur at any time during metoclopramide therapy, the drug
should be discontinued.
Adverse reactions, especially those involving the nervous system, may occur after stopping the use of
reglan®. A small number of patients may experience a withdrawal period after stopping reglan® that
could include dizziness, nervousness, and/or headaches.
Information For Patients
The use of reglan® is recommended for adults only. Metoclopramide may impair the mental and/or
physical abilities required for the performance of hazardous tasks such as operating machinery or
driving a motor vehicle. The ambulatory patient should be cautioned accordingly.
For additional information, patients should be instructed to see the Medication Guide for reglan®
tablets.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
A 77-week study was conducted in rats with oral doses up to about 40 times the maximum recommended
human daily dose. Metoclopramide elevates prolactin levels and the elevation persists during chronic
administration. Tissue culture experiments indicate that approximately one-third of human breast cancers
are prolactin-dependent in vitro, a factor of potential importance if the prescription of metoclopramide is
contemplated in a patient with previously detected breast cancer. Although disturbances such as
galactorrhea, amenorrhea, gynecomastia, and impotence have been reported with prolactin-elevating
drugs, the clinical significance of elevated serum prolactin levels is unknown for most patients. An
increase in mammary neoplasms has been found in rodents after chronic administration of prolactinstimulating
neuroleptic drugs and metoclopramide. Neither clinical studies nor epidemiologic studies
conducted to date, however, have shown an association between chronic administration of these drugs
and mammary tumorigenesis; the available evidence is too limited to be conclusive at this time.
An Ames mutagenicity test performed on metoclopramide was negative.
Pregnancy Category B
Reproduction studies performed in rats, mice and rabbits by the I.V., I.M., S.C., and oral routes at
maximum levels ranging from 12 to 250 times the human dose have demonstrated no impairment of
fertility or significant harm to the fetus due to metoclopramide. There are, however, no adequate and
well-controlled studies in pregnant women. Because animal reproduction studies are not always
predictive of human response, this drug should be used during pregnancy only if clearly needed.
Nursing Mothers
Metoclopramide is excreted in human milk. Caution should be exercised when metoclopramide is
administered to a nursing mother.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established (see OVERDOSE).
Care should be exercised in administering metoclopramide to neonates since prolonged clearance may
produce excessive serum concentrations (see CLINICAL PHARMACOLOGY - Pharmacokinetics).
In addition, neonates have reduced levels of NADH-cytochrome b5 reductase which, in combination
with the aforementioned pharmacokinetic factors, make neonates more susceptible to
methemoglobinemia (see OVERDOSE).
The safety profile of metoclopramide in adults cannot be extrapolated to pediatric patients. Dystonias
and other extrapyramidal reactions associated with metoclopramide are more common in the pediatric
population than in adults. (See WARNINGS and ADVERSE REACTIONS - Extrapyramidal
Reactions.)
Geriatric Use
Clinical studies of reglan® did not include sufficient numbers of subjects aged 65 and over to determine
whether elderly subjects respond differently from younger subjects.
The risk of developing parkinsonian-like side effects increases with ascending dose. Geriatric patients
should receive the lowest dose of reglan® that is effective. If parkinsonian-like symptoms develop in a
geriatric patient receiving reglan® , reglan® should generally be discontinued before initiating any
specific anti-parkinsonian agents (see WARNINGS and DOSAGE AND ADMINISTRATION – For the Relief of Symptomatic Gas troes ophageal Reflux).
The elderly may be at greater risk for tardive dyskinesia (see WARNINGS – Tardive Dys kinesia).
Sedation has been reported in reglan® users. Sedation may cause confusion and manifest as oversedation
in the elderly (see CLINICAL PHARMACOLOGY, PRECAUTIONS – Information for
Patients and ADVERSE REACTIONS – CNS Effects).
reglan® is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug
may be greater in patients with impaired renal function (see DOSAGE AND ADMINISTRATION –
Use in Patients with Renal or Hepatic Impairment).
For these reasons, dose selection for an elderly patient should be cautious, usually starting at the low
end of the dosing range, reflecting the greater frequency of decreased renal function, concomitant
disease, or other drug therapy in the elderly (see DOSAGE AND ADMINISTRATION – For the
Relief of Symptomatic Gastroesophageal Reflux and Use in Patients with Renal or Hepatic
Impairment).
Other Special Populations
Patients with NADH-cytochrome b5 reductase deficiency are at an increased risk of developing
methemoglobinemia and/or sulfhemoglobinemia when metoclopramide is administered. In patients with
G6PD deficiency who experience metoclopramide- induced methemoglobinemia, methylene blue
treatment is not recommended (see OVERDOSE).
Dosage (Posology) and method of administration
Therapy with reglan® tablets should not exceed 12 weeks in duration.
For The Relief Of Symptomatic Gastroesophageal Reflux
Administer from 10 mg to 15 mg reglan® (metoclopramide hydrochloride, USP) orally up to q.i.d. 30
minutes before each meal and at bedtime, depending upon symptoms being treated and clinical response
(see CLINICAL PHARMACOLOGY and INDICATIONS AND USAGE). If symptoms occur only
intermittently or at specific times of the day, use of metoclopramide in single doses up to 20 mg prior to
the provoking situation may be preferred rather than continuous treatment. Occasionally, patients (such
as elderly patients) who are more sensitive to the therapeutic or adverse effects of metoclopramide will
require only 5 mg per dose.
Experience with esophageal erosions and ulcerations is limited, but healing has thus far been
documented in one controlled trial using q.i.d. therapy at 15 mg/dose, and this regimen should be used
when lesions are present, so long as it is tolerated (see ADVERSE REACTIONS). Because of the
poor correlation between symptoms and endoscopic appearance of the esophagus, therapy directed at
esophageal lesions is best guided by endoscopic evaluation.
Therapy longer than 12 weeks has not been evaluated and cannot be recommended.
For the Relief of Symptoms As s ociated with Diabetic Gas tropares is (Diabetic Gas tric Stas is )
Administer 10 mg of metoclopramide 30 minutes before each meal and at bedtime for two to eight
weeks, depending upon response and the likelihood of continued well-being upon drug discontinuation.
The initial route of administration should be determined by the severity of the presenting symptoms. If
only the earliest manifestations of diabetic gastric stasis are present, oral administration of reglan® may
be initiated. However, if severe symptoms are present, therapy should begin with metoclopramide
injection (consult labeling of the injection prior to initiating parenteral administration).
Administration of metoclopramide injection up to 10 days may be required before symptoms subside, at
which time oral administration may be instituted. Since diabetic gastric stasis is frequently recurrent,
reglan® therapy should be reinstituted at the earliest manifestation.
Use In Patients With Renal Or Hepatic Impairment
Since metoclopramide is excreted principally through the kidneys, in those patients whose creatinine
clearance is below 40 mL/min, therapy should be initiated at approximately one-half the recommended
dosage. Depending upon clinical efficacy and safety considerations, the dosage may be increased or
decreased as appropriate.
See OVERDOSE section for information regarding dialysis.
Metoclopramide undergoes minimal hepatic metabolism, except for simple conjugation. Its safe use has
been described in patients with advanced liver disease whose renal function was normal.
Interaction with other medicinal products and other forms of interaction
SIDE EFFECTS
In general, the incidence of adverse reactions correlates with the dose and duration of metoclopramide
administration. The following reactions have been reported, although in most instances, data do not
permit an estimate of frequency:
CNS Effects
Restlessness, drowsiness, fatigue, and lassitude occur in approximately 10% of patients receiving the
most commonly prescribed dosage of 10 mg q.i.d. (see PRECAUTIONS). Insomnia, headache,
confusion, dizziness, or mental depression with suicidal ideation (see WARNINGS) occur less
frequently. The incidence of drowsiness is greater at higher doses. There are isolated reports of
convulsive seizures without clear-cut relationship to metoclopramide. Rarely, hallucinations have been
reported.
Extrapyramidal Reactions (EPS)
Acute dystonic reactions, the most common type of EPS associated with metoclopramide, occur in
approximately 0.2% of patients (1 in 500) treated with 30 to 40 mg of metoclopramide per day.
Symptoms include involuntary movements of limbs, facial grimacing, torticollis, oculogyric crisis,
rhythmic protrusion of tongue, bulbar type of speech, trismus, opisthotonus (tetanus-like reactions), and,
rarely, stridor and dyspnea possibly due to laryngospasm; ordinarily these symptoms are readily
reversed by diphenhydramine (see WARNINGS).
Parkinsonian-like symptoms may include bradykinesia, tremor, cogwheel rigidity, mask-like facies (see WARNINGS).
Tardive dyskinesia most frequently is characterized by involuntary movements of the tongue, face,
mouth, or jaw, and sometimes by involuntary movements of the trunk and/or extremities; movements may
be choreoathetotic in appearance (see WARNINGS).
Motor restlessness (akathisia) may consist of feelings of anxiety, agitation, jitteriness, and insomnia, as
well as inability to sit still, pacing, foot tapping. These symptoms may disappear spontaneously or
respond to a reduction in dosage.
Neuroleptic Malignant Syndrome
Rare occurrences of neuroleptic malignant syndrome (NMS) have been reported. This potentially fatal
syndrome is comprised of the symptom complex of hyperthermia, altered consciousness, muscular
rigidity, and autonomic dysfunction (see WARNINGS).
Endocrine Disturbances
Galactorrhea, amenorrhea, gynecomastia, impotence secondary to hyperprolactinemia (see PRECAUTIONS). Fluid retention secondary to transient elevation of aldosterone (see CLINICAL PHARMACOLOGY).
Cardiovascular
Hypotension, hypertension, supraventricular tachycardia, bradycardia, fluid retention, acute congestive
heart failure and possible AV block (see CONTRAINDICATIONS and PRECAUTIONS).
Gastrointestinal
Nausea and bowel disturbances, primarily diarrhea.
Hepatic
Rarely, cases of hepatotoxicity, characterized by such findings as jaundice and altered liver function
tests, when metoclopramide was administered with other drugs with known hepatotoxic potential.
Renal
Urinary frequency and incontinence.
Hematologic
A few cases of neutropenia, leukopenia, or agranulocytosis, generally without clear-cut relationship to
metoclopramide. Methemoglobinemia, in adults and especially with overdosage in neonates (see OVERDOSE). Sulfhemoglobinemia in adults.
Allergic Reactions
A few cases of rash, urticaria, or bronchospasm, especially in patients with a history of asthma. Rarely,
angioneurotic edema, including glossal or laryngeal edema.
Miscellaneous
Visual disturbances. Porphyria.
DRUG INTERACTIONS
The effects of metoclopramide on gastrointestinal motility are antagonized by anticholinergic drugs and
narcotic analgesics. Additive sedative effects can occur when metoclopramide is given with alcohol,
sedatives, hypnotics, narcotics, or tranquilizers.
The finding that metoclopramide releases catecholamines in patients with essential hypertension
suggests that it should be used cautiously, if at all, in patients receiving monoamine oxidase inhibitors.
Absorption of drugs from the stomach may be diminished (e.g., digoxin) by metoclopramide, whereas
the rate and/or extent of absorption of drugs from the small bowel may be increased (e.g.,
acetaminophen, tetracycline, levodopa, ethanol, cyclosporine).
Gastroparesis (gastric stasis) may be responsible for poor diabetic control in some patients.
Exogenously administered insulin may begin to act before food has left the stomach and lead to
hypoglycemia. Because the action of metoclopramide will influence the delivery of food to the
intestines and thus the rate of absorption, insulin dosage or timing of dosage may require adjustment.