Sominex (Diphenhydramine)

Sominex is used to suppress coughs, to treat motion sickness, to induce sleep, and to treat mild forms of Parkinson's disease.
Sominex is also used to treat sneezing; runny nose; itching, watery eyes; hives; rashes; itching; and other symptoms of allergies and the common cold.
Sominex may also be used for purposes other than those listed in this medication guide.

As a sleep aid, Sominex should be taken approximately 30 minutes before bedtime.
Take each dose with a full glass of water.
Sominex can be taken with or without food.
For motion sickness, a dose is usually taken 30 minutes before motion, then with meals and at bedtime for the duration of exposure.
To ensure that you get a correct dose, measure the liquid forms of Sominex with a special dose-measuring spoon or cup, not with a regular tablespoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.
Never take more of this medication than is prescribed for you. The maximum amount of Sominex that you should take in any 24-hour period is 300 mg.

Sominex is an antihistamine. Sominex blocks the effects of the naturally occurring chemical histamine in the body.

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication unless otherwise directed by your doctor.

Store Sominex at room temperature away from moisture and heat.

Do not take Sominex 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.
Before taking this medication, tell your doctor if you have

• glaucoma or increased pressure in the eye;
• a stomach ulcer;
• an enlarged prostate, bladder problems or difficulty urinating;
• an overactive thyroid (hyperthyroidism);
• hypertension or any type of heart problems; or
• asthma.

Stop taking diphenhydramine and seek emergency medical attention if you experience an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives).

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

• sleepiness, fatigue, or dizziness;
• headache;
• dry mouth; or
• difficulty urinating or an enlarged prostate.

Do not take Sominex 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 Sominex, which could lead to an antihistamine overdose.

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.