Popular Medications That Can Make Your Muscles Weak

Muscle weakness can complicate everyday tasks like picking up a box, lifting ourselves out of bed, or the ability to express emotion if the muscles of the face are affected. Reduced muscle strength can occur for a number of different reasons, some of which may be temporary, like pushing our body to its limit during intense exercise. More long-term causes of muscle weakness may alternatively be related to a chronic health condition. Eventually, muscle weakness can negatively impact our metabolism, posture, and balance, as well as make things harder on our joints, reports Harvard Health Publishing.

If a muscle does not contract or move as it should when stimulated, this is considered muscle weakness, explains Healthline. Muscle weakness unrelated to physical activity or a health condition may instead be a side effect of certain over-the-counter (OTC) or prescription medications. Among some of the more common medications associated with muscle pain are statins, which are prescribed to patients with high cholesterol. Mayo Clinic experts state that patients taking these drugs often report muscles that feel sore, tired, or weak.

Types of prescription drugs that can cause muscle weakness

According to 2022 research published in the International Journal of Molecular Sciences, muscle-related symptoms have been estimated to affect anywhere between 10% and 15% of patients taking statin drugs. Although the exact cause of this relationship is not entirely clear, the calf muscles, thighs, buttocks, and back muscles are among the areas most often affected.

Certain drugs prescribed to treat heart arrhythmias, such as amiodarone, have also been linked with muscle weakness. The same is true for various antithyroid medications used to treat hyperthyroidism, like methimazole (via Medical News Today). Patients taking HIV antivirals like lamivudine or zidovudine may also experience reduced muscle strength. For patients diagnosed with cancer, muscle weakness may occur as a combined result of the disease and chemotherapy treatments. This is known as a condition called cachexia, which is characterized by skeletal muscle wasting (via the American Journal of Cancer Research).

Mental health medications and OTC drugs can also cause muscle weakness

Drugs used to treat our physical health aren't the only kinds of medications that may prompt muscle weakness, however. Certain mental health treatment drugs can also produce this side effect, such as those for depression or anxiety, reports Alberta Health Services.

Muscle weakness can also occur in connection with OTC medicines. This includes popular nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen (via Medical News Today). In a 2018 study published in Acta Physiologica, researchers found that young adults taking high doses of ibuprofen or aspirin while undergoing resistance training for a period of eight weeks experienced decreases in muscle mass and muscle strength. As a result, the researchers cautioned those who regularly engage in resistance training against the overconsumption of NSAIDs.

While we've touched on some of the more popular medications associated with muscle weakness, the list goes on to include drugs like penicillin, corticosteroids, and more. If you experience muscle weakness and suspect that your medications may be involved, be sure to talk to your physician. If muscle weakness comes on abruptly or is accompanied by additional symptoms like confusion, numbness, or difficulty moving or talking, seek urgent medical care.