Symptoms of phenothiazine overdosage include drowsiness or loss of consciousness, hypotension, tachycardia, ECG changes, ventricular arrhythmias and hypothermia. Severe extrapyramidal dyskinesias may occur.
Generalised vasodilatation may result in circulatory collapse; raising the patient's legs may suffice, in severe cases, volume expansion by intravenous fluids may be needed; infusion fluids should be warmed before administration in order not to aggravate hypothermia.
Positive inotropic agents such as dopamine may be tried if fluid replacement is insufficient to correct the circulatory collapse. Peripheral vasoconstrictor agents are not generally recommended; avoid the use of adrenaline.
Ventricular or supraventricular tachy-arrhythmias usually respond to restoration of normal body temperature and correction of circulatory or metabolic disturbances. If they are persistent or life threatening, appropriate anti-arrhythmic therapy may be considered. Avoid lidocaine and, as far as possible, long acting anti-arrhythmic drugs.
Pronounced central nervous system depression requires airway maintenance or, in extreme circumstances, assisted respiration. Severe dystonic reactions usually respond to procyclidine (5--10mg) or orphenadrine (20--40mg) administered intramuscularly or intravenously. Convulsions should be treated with intravenous diazepam.
Neuroleptic malignant syndrome should be treated with cooling. Dantrolene sodium may be tried.
Piportil L4 Depot should not be administered to patients in a comatose state or with marked cerebral atherosclerosis, phaeochromocytoma, renal or liver failure, severe cardiac insufficiency or hypersensitivity to other phenothiazine derivatives. Piportil L4 Depot is also contraindicated in patients with hypersensitivity to pipotiazine palmitate or to any of the excipients.
Piportil L4 Depot injection should not be admixed with any other substance.
Minor side effects of neuroleptics are drowsiness, especially at the start of treatment, nasal stuffiness, dry mouth, insomnia, agitation and weight gain. Other possible adverse effects are listed below.
Liver function: jaundice, usually transient, occurs in a very small percentage of patients taking neuroleptics. A premonitory sign may be a sudden onset of fever after one to three weeks of treatment followed by the development of jaundice. Neuroleptic jaundice has the biochemical and other characteristics of obstructive jaundice and is associated with obstructions of the canaliculi by bile thrombi; the frequent presence of an accompanying eosinophilia indicates the allergic nature of this phenomenon. Treatment should be withheld on the development of jaundice.
Cardiorespiratory: Hypotension, usually postural, commonly occurs. Elderly or volume depleted subjects are particularly susceptible; it is more likely to occur after intramuscular administration.
ECG changes include QT prolongation (as with other neuroleptics), ST depression, U-Wave and T-Wave changes. Cardiac arrhythmias, including ventricular arrhythmias and atrial arrhythmias, a-v block, ventricular tachycardia, which may result in ventricular fibrillation or cardiac arrest have been reported during neuroleptic phenothiazine therapy, possibly related to dosage. Pre-existing cardiac disease, old age, hypokalaemia and concurrent tricyclic antidepressants may predispose.
Cases of venous thromboembolism, including cases of pulmonary embolism and cases of deep vein thrombosis have been reported with antipsychotic drugs - Frequency unknown
There have been isolated reports of sudden death, with possible causes of cardiac origin , as well as cases of unexplained sudden death, in patients receiving neuroleptic phenothiazines.
Blood picture: A mild leukopenia occurs in up to 30% of patients on prolonged high dosage of neuroleptics. Agranulocytosis may occur rarely; it is not dose-related. The occurrence of unexplained infections or fever requires immediate haematological investigation.
Extrapyramidal: Acute dystonias or dyskinesias, usually transitory, are commoner in children and young adults, and usually occur within the first 4 days of treatment or after dosage increases.
- Akathisia characteristically occurs after large initial doses.
- Parkinsonism is commoner in adults and the elderly. It usually develops after weeks or months of treatment. One or more of the following may be seen: tremor, rigidity, akinesia or other features of Parkinsonism. Commonly just tremor.
- Tardive dyskinesia: If this occurs it is usually, but not necessarily, after prolonged or high dosage. It can even occur after treatment has been stopped. Dosage should therefore be kept low whenever possible.
Skin and eyes: contact skin sensitisation is a serious but rare complication in those frequently handling preparations of phenothiazines; the greatest care must be taken to avoid contact of the drug with the skin. Skin rashes of various kinds may also be seen in patients treated with these drugs. Patients on high dosage should be warned that they may develop photosensitivity in sunny weather and should avoid exposure to direct sunlight.
Ocular changes and the development of a metallic greyish-mauve coloration of exposed skin have been noted in some individuals mainly females, who have received chlorpromazine continuously for long periods (four to eight years). Other neuroleptics have been implicated but less frequently.
Endocrine: hyperprolactinaemia which may result in galactorrhoea, gynaecomastia, amenorrhoea; impotence.
Neuroleptic malignant syndrome (hyperthermia, rigidity, autonomic dysfunction and altered consciousness) may occur with any neuroleptic.
Intolerance to glucose, hyperglycaemia.
Pregnancy, puerperium and perinatal conditions; drug withdrawal syndrome neonatal - Frequency not known.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme at: www.mhra.gov.uk/yellowcard
There are no pre-clinical data of relevance to the prescriber which are additional to that already included in other sections of the SPC.
For the maintenance treatment of schizophrenia and paranoid psychoses and prevention of relapse, especially where compliance with oral medication is a problem
Pharmacotherapeutic group: Psycholeptics; Phenothiazines with piperidine structure, ATC code: N05AC04.
Slow release phenothiazine neuroleptic
There is little information about blood levels, distribution and excretion in humans. The rate of metabolism and excretion of phenothiazines decreases in old age
Piportil L4 Depot should be used with caution in patients suffering from or who have a history of, the following conditions: severe respiratory disease, epilepsy, alcohol withdrawal symptoms, brain damage, Parkinson's disease or marked extrapyramidal symptoms with previously used neuroleptics, personal or family history of narrow angle glaucoma, hypothyroidism, myasthenia gravis, prostatic hypertrophy, thyrotoxicosis.8).
Avoid concomitant treatment with other neuroleptics.
Stroke: In randomised clinical trials versus placebo performed in a population of elderly patients with dementia and treated with certain atypical antipsychotic drugs, a 3-fold increase of the risk of cerebrovascular events has been observed. The mechanism of such risk increase is not known. An increase in the risk with other antipsychotic drugs or other populations of patients cannot be excluded. Piportil L4 should be used with caution in patients with stroke risk factors.
Acute withdrawal symptoms, including nausea, vomiting, sweating, and insomnia have been described after abrupt cessation of antipsychotic drugs. Recurrence of psychotic symptoms may also occur, and the emergence of involuntary movement disorders (such as akathisia, dystonia and dyskinesia) has been reported. Therefore, gradual withdrawal is advisable.
Increased Mortality in Elderly people with Dementia
Data from two large observational studies showed that elderly people with dementia who are treated with antipsychotics are at a small increased risk of death compared with those who are not treated. There are insufficient data to give a firm estimate of the precise magnitude of the risk and the cause of the increased risk is not known.
Piportil L4 Depot is not licensed for the treatment of dementia-related behavioural disturbances.
Cases of venous thromboembolism (VTE) have been reported with antipsychotic drugs. Since patients treated with antipsychotics often present with acquired risk factors for VTE, all possible risk factors for VTE should be identified before and during treatment with Piportil L4 Depot and preventative measures undertaken.
Hyperglycaemia or intolerance to glucose has been reported in patients treated with antipsychotic phenothiazines. Patients with an established diagnosis of diabetes mellitus or with risk factors for the development of diabetes who are started on Piportil L4, should get appropriate glycaemic monitoring during treatment.
Patients should be warned about drowsiness especially at the start of treatment and advised not to drive or operate machinery.
Patients should be stabilised on Piportil L4 Depot under psychiatric supervision. Administration should be by deep intramuscular injection into the gluteal region. A wide variation of response can be expected. The following dosage recommendations are suitable for either indication.
| Adults: | Initially 25mg should be given to assess the response of the patient to the drug. Further doses should be administered at appropriate intervals, increasing by increments of 25 or 50 mg until a satisfactory response is obtained. In clinical practice, Piportil L4 Depot has been shown to have a long duration of action, allowing intervals of 4 weeks between injections for maintenance therapy. Dosage should be adjusted under close supervision to suit each individual patient in order to obtain the best therapeutic response compatible with tolerance. The duration of action depends on the dose administered, allowing dosage intervals to be varied to suit individual circumstances. Most patients respond favourably to a dose of 50-100 mg every 4 weeks, the maximum recommended dose is 200 mg every four weeks. |
| Elderly : | Neuroleptics should be used cautiously in the elderly: A reduced starting dose is recommended, i.e. 5-10 mg might be considered. |
| Children: | Not recommended for use in children. |
No special requirements.
