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Phenergan

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Phenergan Drug Description


Phenergan®
(promethazine HCI)
Tablets and Suppositories

DRUG DESCRIPTION

What are the possible side effects of oral promethazine (Pentazine, Phenergan)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using promethazine and call your doctor at once if you have any of these serious side effects:

  • twitching, or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs;
  • tremor (uncontrolled shaking), drooling, trouble swallowing, problems with balance or walking;
  • feeling...

Read All Potential Side Effects for Phenergan »

Each tablet of Phenergan contains 12.5 mg, 25 mg, or 50 mg promethazine HCl. The inactive ingredients present are lactose, magnesium stearate, and methylcellulose. Each dosage strength also contains the following:

12.5 mg-FD&C Yellow 6 and saccharin sodium;
25 mg-saccharin sodium;
50 mg-FD&C Red 40.

Each rectal suppository of Phenergan contains 12.5 mg, 25 mg, or 50 mg promethazine HCl with ascorbyl palmitate, silicon dioxide, white wax, and cocoa butter. Phenergan Suppositories are for rectal administration only.

Promethazine HCl is a racemic compound; the empirical formula is C17H20N2S•HCl and its molecular weight is 320.88.

Promethazine HCl, a phenothiazine derivative, is designated chemically as 10H-Phenothiazine-10-ethanamine, N,N,alpha;-trimethyl-, monohydrochloride, (±)- with the following structural formula:

Phenergan (promethazine HCI) structural formula illustration

Promethazine HCl occurs as a white to faint yellow, practically odorless, crystalline powder which slowly oxidizes and turns blue on prolonged exposure to air. It is freely soluble in water and soluble in alcohol.

Last updated on RxList: 6/21/2007

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Phenergan

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