Today's sleeping pills don't carry the same risks of dependence and lethal overdoses as sleeping pills of the past.  But risks remain — especially for people who have certain medical conditions, including liver and kidney disease.  Here's the lowdown on some of the most common types of sleeping pills used today.

Over-the-counter medications.  

Various over-the-counter sleeping pills are available in any pharmacy.  Many of these medications contain antihistamines, which induce drowsiness by working against the central nervous system chemical histamine.  They're most effective for an occasional sleepless night. The more often you take them, the less effective they become.

Drug	Side effects	Precautions	Considerations
Diphenhydramine (Sominex, Nytol)	May cause dry mouth, dizziness and prolonged drowsiness.	Not recommended for breast-feeding mothers. May not be safe for pregnant women and people who have a history of glaucoma, heart problems or enlarged prostate.	Don't drive or attempt other activities that require alertness while taking this drug.
Doxylamine (Unisom)	May cause prolonged drowsiness.	May not be safe for pregnant women, breast-feeding mothers and people who have a history of asthma, bronchitis, glaucoma, peptic ulcer or enlarged prostate.	Don't drive or attempt other activities that require alertness while taking this drug.

Non-benzodiazepine hypnotic medications

Non-benzodiazepine hypnotic medications are the newest class of sleeping pills.  They quiet the nervous system, which helps induce sleep.  They're metabolized quickly, which helps reduce the risk of side effects the next day.  These medications are mainly intended for short-term or intermittent use.  They're available by prescription only.

Drug	Side effects	Precautions	Considerations
Zolpidem tartrate (Ambien)	May cause dry mouth, diarrhea, dizziness or prolonged drowsiness. In addition, may cause severe allergic reaction, facial swelling and sleep behaviours such as sleep-driving and eating.	May not be safe for people who have a history of depression, liver or kidney disease, or respiratory conditions.	Used mainly to help you fall asleep. Overuse is possible for people experiencing anxiety.
Zaleplon (Sonata)	May cause lightheadedness, abdominal pain, dizziness, headache or prolonged drowsiness. In addition, may cause severe allergic reaction, facial swelling and sleep behaviours such as sleep-driving and eating.	Not recommended for people who have severe liver impairment. May not be safe for pregnant women and people who have a history of depression, liver or kidney disease, or respiratory conditions.	May be used to help you fall asleep or stay asleep.
Eszopiclone (Lunesta)	May cause an unpleasant taste in the mouth, rash, nausea, vomiting, dizziness, headache, depression, swelling, reduced interest in sex or chest pain. In addition, may cause severe allergic reaction, facial swelling and sleep behaviors such as sleep-driving and eating.	May not be safe for pregnant women and people who have a history of drug or alcohol abuse, depression, lung disease or a condition that affects metabolism.	Used mainly to help you stay asleep. May be used for a longer period of time than zolpidem or zaleplon. High-fat meals may slow absorption of the drug and make it less effective. Stopping the drug abruptly may cause withdrawal symptoms.

Benzodiazepine hypnotic medications

Benzodiazepines are an older class of sleeping pills.  They're more likely than newer types to cause drowsiness or headaches the next morning, and they may become habit forming.  Benzodiazepines are available by prescription only.

Drug	Side effects	Precautions	Considerations
Triazolam (Halcion)	May cause lightheadedness, dizziness, prolonged drowsiness or euphoria. Episodes of amnesia have been reported. Rarely, may cause liver failure. In addition, may cause severe allergic reaction, facial swelling and sleep behaviours such as sleep-driving and eating.	Not recommended for pregnant women. May not be safe for breast-feeding mothers and people who have a history of drug abuse, depression or respiratory conditions.	Used mainly to help you fall asleep. May interact with grapefruit juice, alcohol and many other medications. Drug must be stopped gradually.
Estazolam (Prosom)	May cause weakness, coordination problems, dizziness or prolonged drowsiness. In addition, may cause severe allergic reaction, facial swelling and sleep behaviours such as sleep-driving and eating.	Not recommended for pregnant women. May not be safe for breast-feeding mothers and elderly adults.	Used mainly to help you stay asleep. May interact with many other medications.
Temazepam (Restoril)	May cause low blood pressure, diarrhea, nausea, dizziness, headache, prolonged drowsiness or blurred vision. In addition, may cause severe allergic reaction, facial swelling and sleep behaviours such as sleep-driving and eating.	Not recommended for pregnant women. May not be safe for breast-feeding mothers, elderly people and people who have a history of lung disease or severe depression.	Used mainly to help you stay asleep. May interact with alcohol and many other medications.

Sedating antidepressants

Sometimes drugs used mainly to treat depression may ease insomnia when taken in lower doses.  When insomnia is secondary to depression or anxiety, antidepressants can improve both conditions at the same time. Antidepressants are available by prescription only.

Drug	Side effects	Precautions	Considerations
Trazodone (Desyrel)	May cause sweating, weight fluctuations, constipation, diarrhea, nausea, vomiting, headache, dizziness, prolonged drowsiness or blurred vision. Rarely, may cause cardiac complications or seizures.	May not be safe for pregnant women or people who have a history of heart problems or high blood pressure.	May cause abnormal, painful or prolonged erections. Starting with a low dose and increasing gradually may reduce drowsiness and dizziness. Interacts with the blood thinner Coumadin and many herbal supplements.
Amitriptyline	May cause weight gain, bloating, constipation, dizziness, headache, prolonged drowsiness or blurred vision. Rarely, may cause cardiac complications or seizures.	Not recommended during recovery from a heart attack or while using a monoamine oxidase inhibitor. May not be safe for pregnant women or people who have a history of heart problems, seizures, hyperthyroidism, liver disease, schizophrenia or bipolar disorder.	May interact with many other medications.
Nortriptyline (Aventyl, Pamelor)	May cause weight gain, bloating, constipation, dizziness, headache, prolonged drowsiness or blurred vision. Rarely, may cause cardiac complications or seizures.	Not recommended during recovery from a heart attack or while using a monoamine oxidase inhibitor. May not be safe for pregnant women or people who have a history of heart problems, glaucoma, seizures or schizophrenia.	May interact with many other medications.

Dietary supplements

Various dietary supplements have been touted as effective insomnia treatments. The most widely publicized may be the hormone melatonin.

Melatonin is thought to help control your body's internal clock.  The melatonin supplements most often found in health food stores and pharmacies are synthetic versions of the natural hormone.  These supplements may help some people fall asleep or stay asleep.  Melatonin can sometimes help prevent jet lag as well.

There are many unanswered questions about melatonin.  Some people who've taken melatonin have reported drowsiness, headaches, and stomach discomfort.  Confusion, decrease in body temperature, and seizures are also possible, as well as many drug interactions.  The optimal dose isn't certain, and the long-term effects are unknown.

Other supplements — such as valerian, chamomile and kava — have yet to be fully studied for safety or effectiveness in relieving insomnia.

Taking sleeping pills

If your best attempts to get a good night's sleep have failed, over-the-counter or prescription sleeping pills may be an option.  Use them safely.

• Start with your doctor.  You don't need your doctor's OK to take an over-the-counter sleeping aid, but it's a good idea to check with your doctor anyway.  He or she can make sure the sleeping pills won't interact with other medications or medical conditions. Your doctor can also help you determine the best dosage.  In some cases, your doctor may recommend prescription sleeping pills.  If you and your doctor decide further evaluation is needed, you may be referred to a sleep specialist.
• Take it one day at a time.  Sleeping pills are a temporary solution for insomnia.  Most over-the-counter varieties are intended to be used for only two to three nights at a time.  Taken too often, some sleeping pills may cause rebound insomnia — sleeplessness that returns in full force when you stop taking the medication.
• Avoid alcohol. Never mix alcohol and sleeping pills. Alcohol increases the sedative effects of the pills. Even a small amount of alcohol combined with sleeping pills can make you feel dizzy, confused or faint.
• Quit carefully.  When you're ready to stop taking sleeping pills, follow your doctor's instructions or the directions on the label. Some medications must be stopped gradually.
• Watch for side effects.  If you feel sleepy or dizzy during the day, talk to your doctor about changing the dosage or discontinuing the pills.

Everyone deserves a good night's sleep.  If you continue to have trouble sleeping, consult your doctor for additional help.

By Mayo Clinic Staff