Pizotifen

Pizotifen

Clinical data
Trade names	Sandomigran, Mosegor, Litec, others
Other names	Pizotyline; BC-105
AHFS/Drugs.com	International Drug Names
Pregnancy category	AU: B1
Routes of administration	Oral
ATC code	N02CX01 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) CA: ℞-only UK: POM (Prescription only)
Pharmacokinetic data
Bioavailability	78%
Protein binding	91%
Metabolism	Glucuronidation (main route). N-glucuronide accounts for >50% of plasma and 60–70% of urinary excreted drug
Elimination half-life	23 hours
Excretion	18% feces, 55% urine (both as metabolites)
Identifiers
IUPAC name 4-(1-methyl-4-piperidylidine)-9,10-dihydro -4H-benzo-[4,5]cyclohepta[1,2]-thiophene
CAS Number	15574-96-6 Y
PubChem CID	27400
IUPHAR/BPS	93
DrugBank	DB06153 Y
ChemSpider	25497 Y
UNII	0BY8440V3N
KEGG	D05523 Y
ChEMBL	ChEMBL294951 Y
CompTox Dashboard (EPA)	DTXSID6023490
ECHA InfoCard	100.036.014
Chemical and physical data
Formula	C19H21NS
Molar mass	295.44 g·mol−1
3D model (JSmol)	Interactive image
SMILES s1c3c(cc1)C(\c2c(cccc2)CC3)=C4/CCN(C)CC4
InChI InChI=1S/C19H21NS/c1-20-11-8-15(9-12-20)19-16-5-3-2-4-14(16)6-7-18-17(19)10-13-21-18/h2-5,10,13H,6-9,11-12H2,1H3 Y Key:FIADGNVRKBPQEU-UHFFFAOYSA-N Y
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Pizotifen, also known as pizotyline and sold under the brand names Sandomigran and Mosegor among others, is an antimigraine agent of the tricyclic group which is used primarily as a preventative to reduce the frequency of recurrent migraine headaches.^[1]

The main medical use for pizotifen is for the prevention of migraine and cluster headache. Pizotifen is one of a range of medications used for this purpose, other options include propranolol, topiramate, valproic acid, cyproheptadine and amitriptyline. While pizotifen is effective in adults,^[2] evidence of efficacy in children is limited,^[3] and its use is limited by side effects, principally drowsiness and weight gain, and it is usually not the first choice medicine for preventing migraines, instead being used as an alternative when other drugs have failed to be effective.^[4] It is not effective in relieving migraine attacks once in progress.

Pizotifen has also been reported as highly effective in a severe case of erythromelalgia, a rare neurovascular disease that is sometimes refractory to the other drugs named above.^[5]

Other applications for which pizotifen may be used include as an antidepressant, or for the treatment of anxiety or social phobia.^[6][7] Animal studies also suggest that pizotyline could be used in the treatment of serotonin syndrome or MDMA overdose^[8] in a similar manner to the closely related antihistamine/anti-serotonin medication cyproheptadine.

Pizotifen might be useful as a hallucinogen antidote or "trip killer" in blocking the effects of serotonergic psychedelics like psilocybin.^[9] It might also be useful in the treatment of MDMA overdose.^[10]

Caution is required in patients having closed angle glaucoma and in patients with a predisposition to urinary retention as the medication exhibits a relatively small anticholinergic effect. Dose adjustment is required in people who have chronic kidney disease. Liver injury has also been reported. Pizotifen treatment should be discontinued if there is any clinical evidence of liver dysfunction during treatment. Caution is advised in patients having a history of epilepsy. Withdrawal symptoms like depression, tremor, nausea, anxiety, malaise, dizziness, sleep disorder and weight decrease have been reported following abrupt cessation of pizotifen.^[11]

Pizotifen is contraindicated in patients who suffer from hypersensitivity to any of its components or have gastric outlet obstruction, angle-closure glaucoma, and difficulty urinating.^[12] In addition, women who are pregnant should not take pizotifen.^[12]

Side effects include sedation, dry mouth, drowsiness, increased appetite and weight gain.^[13] Occasionally it may cause nausea, headaches, or dizziness. In rare cases, anxiety, aggression and depression may also occur.

Pizotifen is a serotonin antagonist acting mainly at the 5-HT_2A, 5-HT_2B, and 5-HT_2C receptors. It also has some activity as an antihistamine as well as some anticholinergic activity.^[19] The drug binds non-selectively to many targets, including serotonin, dopamine, adrenergic, histamine, and muscarinic acetylcholine receptors.^[10] Besides its serotonin 5-HT₂ receptor antagonism, pizotifen is a low-potency moderate-efficacy partial agonist of the serotonin 5-HT_1A receptor.^[18]

Pizotifen is able to dose-dependently and fully antagonize the discriminative stimulus effects of the serotonin–norepinephrine–dopamine releasing agent and serotonin 5-HT₂ receptor agonist MDMA in rodent drug discrimination tests.^[10] Conversely, the related drug cyproheptadine was only partially effective and clozapine was ineffective.^[10] All three of these agents, pizotifen, cyproheptadine, and clozapine act as non-selective monoamine receptor antagonists.^[10] Pizotifen also fully blocks the effects of serotonergic psychedelics, including LSD, mescaline, 5-MeO-DMT, and DOM, in drug discrimination tests.^[10]

The antimigraine activity of pizotifen might be specifically due to serotonin 5-HT_2B receptor blockade.^[20]

Pizotifen is a tricyclic compound and is specifically a benzocycloheptene.^[21][22]

Close analogues of pizotifen include ketotifen and cyproheptadine, among others.

Pizotifen was first described in the literature by 1964.^[21]

Pizotifen is the generic name of the drug and its INNTooltip International Nonproprietary Name and BANTooltip British Approved Name, while pizotyline is its USANTooltip United States Adopted Name.^[21][22][23] Brand names of pizotifen include Sandomigran, Mosegor, and Litec, among others.^{[21][22][23][24]}

Pizotifen is available widely throughout the world, including in Europe.^[22][24]

• Sandomigran drug data sheet