SANDOMIGRAN (pizotifen malate) S N CH 3 Pizotifen. COOH CH OH CH 2 COOH MALATE DESCRIPTION Pizotifen is a cycloheptathiophene derivative structurally related to cyproheptadine and the tricyclic antidepressants. The malate salt is a white to yellow-tinged crystalline powder. MW = 429.54, pka 6.95 in water. Excipients: silica colloidal anhydrous, lactose, magnesium stearate, starch-maize, talcpurified, povidone, acacia, sucrose, titanium dioxide, cetyl palmitate. PHARMACOLOGY Pharmacodynamics Sandomigran (pizotifen) is a competitive serotonin antagonist. It also possesses antihistamine, antibradykinin and weak anticholinergic properties. It is suitable for the prophylactic treatment of migraine, reducing the frequency of attacks, but is without effect in the migraine attack. The migraine attack is thought to consist of a prodromal phase of constriction followed by dilatation of the extracranial vessels. The mode of action of pizotifen in preventing migraine is not fully understood but it is known to inhibit the reuptake of serotonin by blood platelets, preventing loss of tone of extracranial vessels. It also possesses appetite-stimulating and antidepressant properties. Pharmacokinetics The absorption of pizotifen is rapid (absorption half-life 0.5-0.8 hours) and nearly complete (estimated 80%). Peak plasma levels are achieved 4-6 hours following a single oral dose. Metabolism is extensive and the drug is widely distributed. Volume of distribution is at least 7 litres/kg. Protein binding amounts to 91%. The main metabolite (N-glucuronide) is eliminated 1
with a half-life of about 23 hours. Less than 1% of the drug is excreted in the urine unchanged although as much as 55% of a dose has been detected in the urine as metabolites. In patients with kidney insufficiency dosage adjustment may therefore be necessary. INDICATIONS Prophylactic (interval) treatment of vascular headaches. - typical and atypical migraine - vasomotor headache - cluster headache (Horton's syndrome) Sandomigran is without effect in the migraine attack. For this purpose preparations containing ergotamine are recommended. CONTRAINDICATIONS Hypersensitivity to pizotifen or any of the excipients in the formulation. PRECAUTIONS Renal impairment Caution is required in patients with renal impairment. Dosage adjustment may be necessary. Hepatic impairment Caution is required in patients with hepatic impairment. Dosage adjustment may be necessary. Hepatic injury has been reported, ranging from transaminase elevations to severe hepatitis. Pizotifen treatment should be discontinued if there is any clinical evidence of hepatic dysfunction during treatment and until the cause of the liver abnormality is determined. Withdrawal symptoms Withdrawal symptoms like depression, tremor, nausea, anxiety, malaise, dizziness, sleep disorder and weight decreased have been reported following abrupt cessation of pizotifen (see ADVERSE REACTIONS), therefore gradual withdrawal is recommended. Effects on the ability to drive and use machines: Patients should be warned that Sandomigran may cause sedation, somnolence and dizziness. Therefore, caution should be exercised when driving or using machines. 2
Patients being treated with Sandomigran and presenting with sedation and/or somnolence episodes must be instructed to refrain from driving or engaging in activities where impaired alertness may put themselves or others at risk. Anticholinergic effects: In view of the very slight anticholinergic effect of pizotifen, caution is required in patients with narrow angle glaucoma (except those successfully treated by surgery) or urinary retention (e.g. prostatic enlargement). Up to now no untoward reactions have been reported in such patients given the recommended dosage. Use in Pregnancy (Category B1) No embryotoxic or teratogenic effects were observed in animal studies and fertility was unimpaired. Clinical data with pizotifen in pregnancy are very limited; it should be administered in pregnancy only if the expected benefits outweigh any potential risks. Use in Lactation Animal studies show that pizotifen enters the milk. Although the concentrations of pizotifen measured in the milk of treated mothers are not likely to affect the infant, its use in nursing mothers is not recommended. Use in Children Experience in children is still limited. Interactions with other medicines The following drugs may exhibit drug interactions with pizotifen upon concomitant administration. Anticipated drug interactions to be considered Pizotifen is extensively metabolized in the liver, primarily by N-glucuronidation. Increased plasma concentration of pizotifen upon concomitant administration of drugs which exclusively undergo glucuronidation can not be excluded. Central nervous system agents: Central effects of sedatives, hypnotics, antihistamines, including certain common cold preparations, and alcohol may be enhanced. Monoamine oxidase inhibitors: MAOIs can prolong and intensify the anticholinergic effects of antihistaminic substances. Concomitant use with MAOIs should therefore be avoided. Cisapride: Concomitant administration of pizotifen with cisapride may lead to reduced efficacy of cisapride. 3
Epilepsy Seizures as undesirable effects have been observed more frequently in patients with epilepsy. Pizotifen should be used with caution in patients with epilepsy. Sandomigran coated tablets contain lactose. Patients with rare hereditary problems of galactose intolerance, severe lactase deficiency or glucose-galactose malabsorption should not take Sandomigran. ADVERSE REACTIONS The most common reactions are appetite-stimulating effect, increase in body weight and sedation (including somnolence and fatigue). It can usually be avoided by increasing the dosage gradually or reversed by a progressive reduction in dosage. The appetite-stimulating effect of pizotifen may lead to an increase in body weight. The following adverse reactions are ranked under headings of frequency; the most frequent first, using the following convention: Very common ( 1/10); common ( 1/100, < 1/10); uncommon ( 1/1000, < 1/100); rare ( 1/10,000, < 1/1000); very rare (< 1/10,000), including isolated reports. Immune system disorders Hypersensitivity reactions, face oedema Metabolism and nutrition disorders Very common: Increased appetite and body weight increased Psychiatric disorders Depression, CNS stimulation (e.g. aggression, agitation), hallucination, insomnia, anxiety Nervous system disorders Common: Sedation (including somnolence), dizziness Paraesthesia Very rare: Seizures Gastrointestinal disorders Common: Nausea, dry mouth Uncommon Constipation Skin and subcutaneous tissue disorders Urticaria, rash Musculoskeletal and connective tissue disorders Myalgia General disorders and administration site conditions Common Fatigue 4
Headache, hypotension and impotence have also been reported during treatment with Sandomigran, but a causal relationship was not established. Adverse drug reactions from post-marketing spontaneous reports The following additional adverse drug reactions have been identified with pizotifen based on post-marketing spontaneous reports. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency. Hepatobiliary disorders Unknown: Hepatic enzyme increased, jaundice, hepatitis Musculoskeletal and connective tissue disorders Unknown: Muscle cramps Withdrawal symptoms Withdrawal reactions have been reported following abrupt cessation of pizotifen, therefore gradual withdrawal is recommended (see PRECAUTIONS). Withdrawal symptoms may include: depression, tremor, nausea, anxiety, malaise, dizziness, sleep disorder and weight decreased. DOSAGE AND ADMINISTRATION The dosage should be progressively increased, starting with 0.5 mg daily. The average maintenance dosage is 1.5 mg daily in single or divided doses. Recent studies have shown a single daily dose of 3 tablets (1.5 mg) taken at night to be effective. In refractory cases the dosage may be gradually raised to 3-4.5 mg daily in two or three divided doses. OVERDOSAGE Symptoms Symptoms which may be expected are: drowsiness, nausea, dry mouth, tachycardia, pyrexia, hypotension, dizziness, excitatory states (in children), respiratory depression, convulsions (particularly in children), coma. Treatment Treatment is gastric lavage followed by administration of activated charcoal. If necessary, symptomatic treatment should be given including monitoring of the cardiovascular and respiratory symptoms; for excitatory states or convulsions: benzodiazepines. 5
PRESENTATION Tablets containing 0.5 mg pizotifen present as 0.725 mg pizotifen malate (off-white, sugar-coated); 100's. Store below 30 C. Protect from light. SPONSOR NOVARTIS Pharmaceuticals Australia Pty. Ltd. ABN 18 004 244 160 54 Waterloo Road, NORTH RYDE, NSW 2113 Approved by the Therapeutic Goods Administration: 05.12.86 Date of most recent amendment: 5 May 2011 6