Medications that can leave you tired

Why medication-related fatigue is easy to miss

Tiredness often creeps in gradually, weeks after a new medication or dose increase, so the connection isn't obvious. It can also come from interactions: two mildly sedating drugs together may cause far more drowsiness than either alone.

Older adults and people with kidney or liver problems clear many drugs more slowly, so a dose that was fine at 40 may feel heavier at 60.

Medication groups commonly linked to fatigue

MedlinePlus lists sedatives, antidepressants, antihistamines, blood pressure medicines, sleeping pills, steroids and diuretics among the medications that can cause fatigue. Here is how those groups tend to show up in practice.

• Antihistamines: older allergy and sleep products such as diphenhydramine are notably sedating and can cause next-day grogginess.
• Sleep aids and sedatives: prescription sleep medicines, benzodiazepines and some muscle relaxants can leave a hangover effect.
• Blood pressure drugs: beta blockers can reduce exercise tolerance and energy; diuretics may lower potassium or sodium, which can cause weakness.
• Antidepressants and mood medicines: some are sedating, especially at the start or after a dose increase; others can disturb sleep.
• Opioid pain medicines: commonly cause drowsiness, and long-term use can lower sex hormones, adding to fatigue.
• Corticosteroids: can disturb sleep while taking them, and stopping long-term steroids too quickly can cause severe fatigue from adrenal suppression.
• Anti-seizure and nerve pain medicines: drowsiness is a common side effect.
• Some heartburn, nausea and bladder medicines can also have sedating or anticholinergic effects.

Indirect ways medications drain energy

Some drugs don't sedate you but cause a problem that leads to fatigue. Long-term acid-suppressing medicines and metformin have been associated with lower vitamin B12 over time. Diuretics can shift electrolytes. Overtreatment with thyroid medicine can cause poor sleep and a wired-but-tired feeling, while undertreatment leaves you sluggish.

Blood pressure or diabetes medicines that work too well can also cause tiredness through low blood pressure or low blood sugar, especially after weight loss or other changes in your health.

Alcohol, cannabis and supplements count too

Alcohol amplifies the sedating effect of many medicines and disrupts sleep later in the night. Cannabis products and some herbal sleep remedies also add to drowsiness. When you list your medications for a clinician, include these along with vitamins and supplements.

How to check whether a medication is the cause

Start by lining up a timeline: when did the fatigue start, and what changed around then? New prescriptions, dose increases, switching brands or adding an over-the-counter product are all relevant.

• Make a complete list, including doses, timing, supplements and occasional products.
• Mark anything started or changed in the three months before the fatigue began.
• Ask your prescriber or pharmacist whether timing could be changed, for example moving a sedating drug to bedtime.
• Ask whether a dose reduction or an alternative with fewer sedating effects exists.
• Get basic labs, such as electrolytes, B12, blood count and thyroid function, if your medications make deficiencies more likely.

Don't stop medicines abruptly

Stopping some medications suddenly can be dangerous. Beta blockers can cause rebound high blood pressure or heart rhythm problems, benzodiazepines and some antidepressants can cause withdrawal, and steroids can trigger adrenal crisis. Always plan changes with the prescriber.

Medications that can disturb sleep

Fatigue isn't always from sedation. Some drugs keep you awake at night, which leaves you tired the next day. Steroids, decongestants, some antidepressants, thyroid medicine taken in excess, and diuretics taken late in the day (which cause nighttime urination) are common examples.

If your tiredness comes with poor sleep rather than drowsiness, ask whether the timing of any medicine could be moved earlier in the day.

Older adults and multiple prescriptions

The more medicines you take, the higher the chance of interactions and additive side effects. A periodic medication review with your doctor or pharmacist, sometimes called a brown-bag review, helps catch duplicates, outdated prescriptions and combinations that cause drowsiness.

When to seek urgent care

Get help right away for extreme drowsiness, confusion, slowed breathing, fainting, a very slow pulse, or severe weakness after starting a medicine, particularly opioids, sedatives or a new combination. These can signal an overdose or a serious reaction. Call 911 in an emergency.