THERAPEUTICS

Brands

• Periactin, Cypromar, Periavit, Pyrohep

Generic?

• Yes

Class

• Antihistamine

Commonly Prescribed for

(FDA approved in bold)

• Hypersensitivity reactions

• Migraine prophylaxis (children and adults)

• Tension-type headache prophylaxis

• Nightmares/post-traumatic stress disorder

• Serotonin syndrome

How the Drug Works

• As an antagonist, it has high affinity for histamine (H1), muscarine (M1–5), serotonin (5-HT1A/2A/2B/2C, serotonin transporter), and dopamine (D3) receptors and perhaps for calcium channel receptors. The relative importance of each action in headache prophylaxis is unclear. Prevention of cortical spreading depression may be one mechanism of action for all migraine preventatives

How Long Until It Works

• Migraines may decrease in as little as 2 weeks, but can take up to 2 months to see full effect

If It Works

• Migraine: goal is a 50% or greater decrease in migraine frequency or severity. Consider tapering or stopping if headaches remit for more than 6 months or if considering pregnancy

If It Doesn't Work

• Increase to highest tolerated dose

• Migraine: address other issues, such as medication overuse, other coexisting medical disorders, such as anxiety, and consider changing to another agent or adding a second agent

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Migraine: for some patients with migraine, low-dose polytherapy with 2 or more drugs may be better tolerated and more effective than high-dose monotherapy. May use in combination with AEDs, antidepressants, natural products, and non-medication treatments, such as biofeedback, to improve headache control

Tests

• Monitor weight during treatment

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• Most are related to antihistamine and anticholinergic activity

Notable AEs

• Sedation, dizziness, dry mouth, postural hypotension, photosensitivity, and weight gain

Life-Threatening or Dangerous AEs

• Bradycardia, ECG changes, including QTc prolongation

• Hypersensitivity reactions

Weight Gain

• Problematic

Sedation

• Common