Alpha-blockers are linked to decreased REM (rapid eye movement) sleep — the stage of sleep when people dream — and daytime sedation or sleepiness. The proportion of REM sleep drops markedly in old age, and people deprived of REM sleep can experience memory problems.
Beta-blockers have long been associated with sleep disturbances, including awakenings at night and nightmares. They are thought to do this by inhibiting the nighttime secretion of melatonin, a hormone involved in regulating both sleep and the body’s circadian clock. Low levels of melatonin have sometimes been observed in chronic insomnia.
People often ask why a drug that reduces inflammation would keep them awake. The answer lies in the adrenal glands, which are responsible for regulating the body’s fight-or-flight response. Too much stress can keep the body awake and the mind stimulated by exhausting the adrenal glands; corticosteroids can do the same thing, wreaking havoc on all the systems that allow you to relax and sleep, causing insomnia and unpleasant dreams.
4. SSRI antidepressants
Just as it isn’t known exactly how SSRIs work, it isn’t known exactly how these drugs interfere with sleep. Studies have shown, however, that SSRIs cause agitation, insomnia, mild tremor and impulsivity in 10 percent to 20 percent of the people who take them. Although about half of people who take SSRIs say that the drugs make them feel better, many continue to struggle with symptoms that can make life miserable, especially insomnia. We know this from researchers at the University of Texas Southwestern Medical Center in Dallas, who combed through data from the STAR*D trial, the largest and longest study ever done on depression treatment, and published their findings in 2011. Almost all of the subjects in the Star*D trial, which was funded by the National Institute of Mental Health, said they continued to have problems with insomnia, with 81 percent reporting being unable to sleep in the middle of the night.
5. ACE inhibitors
ACE inhibitors boost the body’s levels of bradykinin, a peptide that enlarges blood vessels. Bradykinin is thought to be the cause of the hacking, dry cough that up to a third of all patients who take an ACE inhibitor develop. This chronic, round-the-clock cough can be severe enough to keep anyone awake. ACE inhibitors can also cause potassium to build up in the body (another type of electrolyte imbalance) and lead to diarrhea, as well as leg cramps and achy joints, bones and muscles — all of which can disturb normal sleep.
Like ACE inhibitors, ARBs frequently lead to potassium overload in the body, causing diarrhea as well as leg cramps and achy joints, bones and muscles — all of which can disturb normal sleep.
7. Cholinesterase inhibitors
These drugs are thought to work by inhibiting the enzyme in the body that breaks down acetylcholine (a neurotransmitter that’s important for alertness, memory, thought and judgment) and thus boosting the amount available to brain cells. This, in theory, slows the patient’s loss of memory and helps him or her perform daily activities with fewer problems. But blocking the breakdown of acetylcholine — which is everywhere in the body, not just in the brain — can interfere with all kinds of involuntary body processes and movements, including those related to sleep. In addition to insomnia and abnormal dreams, the identified side effects of cholinesterase inhibitors include serious changes in heart rhythm, diarrhea, nausea and vomiting as well as leg cramps and muscle spasms — all of which can interfere with normal sleep patterns.
8. H1 antagonists
In varying degrees, all H1 antagonists block acetylcholine, a nervous system neurotransmitter, and thus can cause anxiety and insomnia.
Researchers aren’t sure exactly how glucosamine and chondroitin work, but studies identify a range of gastrointestinal side effects, including nausea and diarrhea, as well as headaches and insomnia.
The most common side effect of all types of statins is muscle pain, which can keep people who take them awake at night and unable to rest. In the worst cases, the pain caused by statins can be immobilizing. Researchers have found that fat-soluble statins are more likely to cause insomnia or nightmares because they can more easily penetrate cell membranes and make their way across the blood-brain barrier, which protects the brain from chemicals in the blood.