What is diphenhydramine?
Diphenhydramine is an antihistamine. Diphenhydramine blocks the effects of the naturally occurring chemical histamine in the body. Diphenhydramine is used to treat sneezing; runny nose; itching, watery eyes; hives; rashes; itching; and other symptoms of allergies and the common cold. Diphenhydramine is also used to suppress coughs, to treat motion sickness, to induce sleep, and to treat mild forms of Parkinson's disease. Diphenhydramine may also be used for purposes other than those listed in this medication guide.
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What is the price of this medication and similar alternatives?
Pricing information provided by drugstore.com.
| DiphenhydrAMINE HCl 50MG/ML SOLN | BAXTER HEALTHCARE CORPORATION | 25/$29 or 50/$57.99 |
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What are the possible side effects of diphenhydramine?
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
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sleepiness, fatigue, or dizziness;
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headache;
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dry mouth; or
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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.
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How should I take diphenhydramine?
Take diphenhydramine exactly as directed on the package or as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water. Diphenhydramine 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. As a sleep aid, diphenhydramine should be taken approximately 30 minutes before bedtime.
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What is the most important information I should know about diphenhydramine?
Use caution when driving, operating machinery, or performing other hazardous activities. Diphenhydramine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while taking diphenhydramine.
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What happens if I miss a dose?
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.
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What other drugs will affect diphenhydramine?
Do not take diphenhydramine 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 diphenhydramine, which could lead to an antihistamine overdose. Before taking this medication, tell your doctor if you are taking any of the following medicines:
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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?
Diphenhydramine has been assigned to pregnancy category B by the FDA. Animal studies have failed to reveal teratogenicity. The Collaborative Perinatal Project reported 595 first-trimester exposures and 2,948 exposures anytime during pregnancy. No relationship was found to large categories of malformations. Possible associations with individual malformation were found. One study reported a statistical relationship between diphenhydramine use in the first trimester and cleft palate. One case of withdrawal in an infant whose mother ingested 150 mg per day of diphenhydramine has been reported. This infant developed tremor on the fifth day of life which was treated with phenobarbital. Diphenhydramine is only recommended for use during pregnancy only when benefit outweighs risk.
A review of prenatal drug use in 3026 women with premature infants demonstrated an increased risk of retrolental fibroplasia with antihistamine use during the last two weeks of pregnancy. The dosage used or the particular antihistamine was not specified. The incidence of retrolental fibroplasia in premature infants exposed in utero to antihistamine during this time was 21% compared to 11% in premature infants not exposed.
Diphenhydramine has been shown to have oxytocic effects in animal and human uteri. One case report of a pregnant woman who ingested a large amount of diphenhydramine in an attempted suicide developed strong, regular uterine contractions that were halted by the administration of intravenous magnesium.
Diphenhydramine is excreted into human milk. Diphenhydramine may also inhibit lactation. The manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
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Who should NOT use this medication?
- Use contraindicated in neonates and premature infants. (See Pediatric Use under Cautions.)
- Women who are breast-feeding. (See Lactation under Cautions.)
- Injection should not be used as a local anesthetic. (See Local Necrosis under Cautions.)
- Concomitant use with other preparations containing diphenhydramine, including oral and topical preparations.
- Known hypersensitivity to diphenhydramine, other antihistamines with similar chemical structure, or any ingredient in the formulation.
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What does my medication look like?
Diphenhydramine is available with a prescription and over the counter generically and under many brand names as tablets, capsules, an elixir, 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.
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What happens if I overdose?
Seek emergency medical attention if an overdose is suspected. Symptoms of a diphenhydramine overdose include extreme sleepiness, confusion, weakness, ringing in the ears, blurred vision, large pupils, dry mouth, flushing, fever, shaking, insomnia, hallucinations, and possibly seizures.
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What should I discuss with my healthcare provider before taking diphenhydramine?
Do not take diphenhydramine 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
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Can I stop taking the medication if I feel better?
As a general rule, you should always take your medications exactly as prescribed and do not change the dosage or stop taking the medication without first discussing it with your healthcare provider.
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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.
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Where can I get more information?
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