• Basic Info
• Top Questions
• Clinical Info
• Interactions

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a chlorpheniramine overdose include extreme sleepiness, confusion, weakness, ringing in the ears, blurred vision, large pupils, dry mouth, flushing, fever, shaking, insomnia, hallucinations, and possibly seizures.

What should I avoid while taking chlorpheniramine?

Use caution when driving, operating machinery, or performing other hazardous activities. Chlorpheniramine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking chlorpheniramine.

What are the possible side effects of chlorpheniramine?

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.

What other drugs will affect chlorpheniramine?

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.

Where can I get more information?

Your pharmacist has more information about chlorpheniramine written for health professionals that you may read.

What does my medication look like?

Chlorpheniramine is available both with a prescription and over the counter under many brand and generic names as regular tablets, chewable tablets, timed-release tablets, and a syrup. Other formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.