• Basic Info
• Top Questions
• Clinical Info
• Interactions

Do not take chlorpheniramine if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the last 14 days. A very dangerous drug interaction could occur, leading to serious side effects.

Talk to your pharmacist before taking other over-the-counter cough, cold, allergy, or insomnia medications. These products may contain medicines similar to chlorpheniramine, which could lead to an overdose of antihistamine.

Before taking this medication, tell your doctor if you are taking any of the following medicines:

• anxiety or sleep medicines such as alprazolam (Xanax), diazepam (Valium), chlordiazepoxide (Librium), temazepam (Restoril), or triazolam (Halcion);

• medications for depression such as amitriptyline (Elavil), doxepin (Sinequan), nortriptyline (Pamelor), fluoxetine (Prozac), sertraline (Zoloft), or paroxetine (Paxil); or

• any other medications that make you feel drowsy, sleepy, or relaxed.

Drugs other than those listed here may also interact with chlorpheniramine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

If you experience an allergic reaction to chlorpheniramine including swelling of your lips, tongue, or face, difficulty breathing, closing of your throat, or hives, stop taking it and seek emergency medical attention.

Other, less serious side effects may be more likely to occur. Continue to take chlorpheniramine and talk to your doctor if you experience

• sleepiness, fatigue, or dizziness;

• headache;

• dry mouth; or

• difficulty urinating or an enlarged prostate.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.