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Which medications make you sleepy?

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 3, 2022.

Official answer


Many medications can make you sleepy – some intentionally – such as sleeping pills, but others can make you tired as a side effect or an unintended consequence of the medication. It is important to know before taking a medication if there is a chance it may make you sleepy, drowsy, tired, or fatigued, because this may have an impact on your driving or ability to operate machinery, and how competent you are to make good decisions. 13 common classes of medications that can make you sleepy include:


Drowsiness or fatigue are not common side effects of antibiotics, but these side effects have been reported by some people. Amoxicillin, azithromycin, and ciprofloxacin seem to be the more likely to cause sleepiness.


There are two main types of antihistamines: those that are sedating (cause drowsiness) and those that are non-sedating. Although non-sedating antihistamines do not usually cause drowsiness, they may do so in some people. Examples of antihistamines include:


There are at least seven different classes of antidepressants, some more sedating than others. In general, tricyclic antidepressants tend to be the most sedating, but other types of antidepressants, such as MAOIs and SSRIs, can cause either insomnia or sleepiness. For example:

Antinausea medications

Such as metoclopramide, cyclizine, and ondansetron can also cause drowsiness in some people.


If you have recently started taking an antipsychotic, or had your dosage increased, then you are more likely to feel sleepy – at least in the first few weeks. Research has also identified some antipsychotics as being more likely to cause drowsiness than others:

Anxiety medications

Traditional anti-anxiety medications, such as benzodiazepines, all cause drowsiness. Examples include alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium), and lorazepam (Ativan). Other anxiolytics, such as buspirone (BuSpar), hydroxyzine (Atarax), and venlafaxine (Effexor XR) can also cause drowsiness.

Cancer treatments

Fatigue and sleepiness are common side effects of many different cancer medications, such as chemotherapy and immunotherapy, as well as certain cancer treatments such as radiation therapy. 9 out of 10 people with cancer experience fatigue and common classes of cancer medications that may cause sleepiness include alkylating agents, antimetabolites, monoclonal antibodies (eg, Keytruda, Libtayo, Opdivo, Tecentriq, Yervoy, Blincyto, Monjuvi), PARP inhibitors, and immunotherapy.

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Heart medications

Many different types of heart medications can cause tiredness because they slow down the heart, reduce blood pressure, depress the central nervous system, or deplete electrolytes that the body needs, which can make you feel tired. Examples include:

  • ACE Inhibitors such as lisinopril (Prinivil, Zestril)
  • Beta blockers: Slow down the heart rate which slows down the amount of blood pumped through the heart which can make you feel tired, fatigued, or drowsy. Examples include: acebutolol (Sectral), atenolol (Tenormin), bisoprolol (Zebeta), metoprolol (Lopressor), and sotalol (Betapace)
  • Calcium channel blockers, such as amlodipine (Norvasc)
  • Diuretics: Reduce electrolytes in the blood which can make you feel tired or lacking in energy. Examples include furosemide (Lasix) or HCTZ
  • Renin inhibitors, such as aliskiren (Tekturna)

High cholesterol medications

Statins and fibrates can cause tiredness and fatigue by reducing the supply of energy to muscle cells. Examples include:

Muscle relaxants

These tend to act on your nerves rather than directly on your muscles which can cause sedation, fatigue, drowsiness, and tiredness. Examples include baclofen (Lioresal), diazepam (Valium), carisoprodol (Soma), cyclobenzaprine (Flexeril), and orphenadrine (Norflex).

Pain medications

Opioids act on the central nervous system and sedation is a common side effect although experts are unsure how this effect happens. Examples include morphine, fentanyl, oxycodone, hydrocodone, and codeine, as well as combination treatments containing these medications. Tramadol may also cause drowsiness.

Proton pump inhibitors (PPIs)

Using PPIs for longer than 3 months can deplete magnesium levels in the body, which can cause loss of appetite, difficulty sleeping, fatigue, and weakness. Examples include dexlansoprazole, esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), and pantoprazole (Protonix).

Seizure or epilepsy medications (anticonvulsants)

Drowsiness is one of the most common side effects of anticonvulsants because they are thought to modify sleep architecture and the sleep-wake cycle, and disrupt sleep. Daytime sleepiness can be severe. Examples of anticonvulsants that can cause sedation include carbamazepine (Tegretol), phenobarbital, phenytoin (Dilantin), topiramate (Topamax), and valproic acid (Depakote).

What can you do if your medication makes you sleepy?

A lot of medications that cause drowsiness do so initially, but then your body builds up a tolerance to this effect. You could try taking your medicine at night and see if you still feel tired during the day. Give your body time to adjust to the medication but if you are still feeling sleepy after 2 weeks, or the sleepiness is affecting your day-to-day activities or your ability to drive, talk to your doctor.

Another option is to talk to your doctor about possibly reducing the dosage, and then slowly increasing it again over a few weeks. Do not do this yourself without your doctor’s advice.

Making sure you get enough sleep every night, can help combat the feeling of drowsiness your medication may be causing. Try to go to bed at the same time each night and get up at the same time each morning. Aim for 7 to 8 hours of sleep a night and avoid naps during the day. Avoid TV, exercise, alcohol, and caffeine at least an hour before bed.

Avoid alcohol. Alcohol can increase the side effects of medications, such as drowsiness. Also, check with your doctor and pharmacist about any other medications you may be taking that also cause drowsiness because these can have a compounding effect.

  • Fang, F., Sun, H., Wang, Z., Ren, M., Calabrese, J. R., & Gao, K. (2016). Antipsychotic Drug-Induced Somnolence: Incidence, Mechanisms, and Management. CNS drugs, 30(9), 845–867.
  • Combating drowsiness caused by antipsychotics. Psych Central. Feb 10, 2021.
  • What to do when medication makes you sleepy. Oct 1, 2019. Harvard Health Publishing Harvard Medical School.
  • Neel A. 9 Types of Medications That Can Lead to Chronic Fatigue. AARP.
  • Burstein, R., Hourvitz, A., Epstein, Y., Dvir, Z., Moran, D., Altar, J., Shemer, J., Shalev, A., & Galun, E. (1993). The relationship between short-term antibiotic treatments and fatigue in healthy individuals. European journal of applied physiology and occupational physiology, 66(4), 372–375.
  • Can Antibiotics Make You Tired? K Health. Oct 25, 2021.,amoxicillin%2C%20azithromycin%2C%20and%20ciprofloxacin.

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