US Pharm
. 2009;34(11):12-15. 

Fatigue and drowsiness are a part of everyday life for millions of people, and prolonged fatigue is a concern for 10% to 25% of those who visit general practitioners.1 The high incidence of fatigue is due to such issues as today’s hectic lifestyle, lack of leisure time, poor sleep habits, and certain medical conditions. Pharmacists are in an ideal position to provide assistance to patients complaining about continual fatigue and daytime drowsiness. 


Fatigue is commonly experienced and is the feeling of tiredness or exhaustion that follows a hard day of work or mentally and physically challenging exercise.2,3 Patients may also complain that they are weary, that their energy is gone, or that they feel lack of motivation to accomplish other tasks. 

Counseling Patients With Fatigue: When counseling patients with fatigue, the pharmacist should first attempt to ascertain whether the fatigue is a normal response to overwork or a continual problem that seems unrelated to the amount or extent of effort performed that day, week, or month. If it is the former, the problem is probably a short-term, minor difficulty that will resolve on its own once the stressors have subsided. However, if the patient is able to sleep normally but still experiences continual fatigue that seems unrelated to ongoing mental or physical stress, the fatigue may be secondary to medications or a medical condition.3 For example, patients with hypothyroidism complain that they awaken refreshed, but that activity results in rapid onset of fatigue.3 

Causes of Fatigue: Fatigue can be caused by a wide variety of medical conditions.1,3,4 As many as 40% of those reporting symptoms of chronic fatigue were eventually discovered to have a psychiatric or medical condition that had not yet been diagnosed but was ultimately treated successfully.4 Etiologies include premenstrual syndrome, premenstrual dysphoric disorder, allergic rhinitis, asthma, anemias, hypo- or hyperthyroidism, Addison’s disease, fibromyalgia, arthritis, lupus, cancer, Parkinson’s disease, congestive heart failure, diabetes, conditions causing persistent pain, infections (e.g., AIDS, mononucleosis), renal disease, and hepatic disease.4-8 Depression and grief induce fatigue. Sleep disorders cause fatigue, including insomnia, narcolepsy, and obstructive sleep apnea. Alcohol and other drugs of abuse (e.g., cocaine, narcotics) cause fatigue, and the patient may find that making healthier lifestyle choices will resolve the problem. Malnutrition leads to fatigue, as do anorexia and other eating disorders. The wide spectrum of potential etiologies makes it critical for pharmacists to refer patients with unexplained fatigue to a physician for a full medical evaluation. 

Chronic Fatigue Syndrome: Chronic fatigue syndrome (CFS) is a cause of chronic tiredness that affects 1 to 4 million Americans.4 Its ramifications are profound, in that one-fourth of sufferers are not employed and many are receiving disability benefits. It differs from normal fatigue in its severity, in the incapacitating feeling that patients experience, and in the fact that bed rest does not relieve it.1,9 The degree of fatigue limits or halts social engagements, educational efforts, work, and personal activity. Studies from the CDC reveal that the disabling effects of CFS rival those of such overwhelming conditions as chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, lupus, multiple sclerosis, heart disease, and end-stage renal disease. 

The degree of disability varies widely among patients and in the same patient from episode to episode. Some patients experience periods where they are relatively free of symptoms, followed by a period of extreme disability.1 This cyclical pattern is often seen with CFS. 

To meet the formal diagnosis of CFS, patients should have experienced symptoms for 6 months or more.1 Further, the fatigue is not caused by any underlying medical conditions and is accompanied by such nonspecific ancillary symptoms as sore throat, joints that are painful but lack erythema or inflammation, unrelenting muscle pain, headaches that differ from the norm in severity or symptoms, and lymph node tenderness (axillary or cervical).1 Patients do not feel refreshed after sleep, and they also notice that physical or mental exercise produces a malaise that persists for more than 24 hours. Their ability to concentrate on tasks is reduced, and their memory is impaired. These are referred to as the eight symptoms that define CFS. 

Treatment options for CFS are diverse and of variable use. The CDC urges practitioners to adapt treatment plans to the individual patient’s present symptoms.10 Sleep disturbances may be initially treated with simple sleep hygiene measures, followed by nonprescription antihistamine sleep aids such as Sominex and Unisom. If these medications are needed beyond 14 days, however, the patient should be urged to seek care from a physician. Muscle and joint pain and headache may be amenable to nonprescription acetaminophen, ibuprofen, or naproxen. 

The CDC alerts patients to the fallacies of using nutritional and herbal supplements for CFS.10 Although some patients report relief from these products, they are not regulated by the FDA, and thus objective data to prove their efficacy and safety are often lacking. The CDC warns patients against such herbs as comfrey, ephedra, kava, germander, chaparral, bitter orange, licorice root, and yohimbine due to reports of toxicity coupled with lack of efficacy data.10 

The CDC also mentions the use of alternative therapies such as acupuncture, aquatic therapy, gentle massage, meditation, deep breathing, biofeedback, yoga, and tai chi.10 The agency urges patients to discuss these options with a health care provider to make sure that they have been proven safe and effective. 

Medications That Cause Fatigue: Medications that are reported to cause fatigue include antihistamines, antihypertensives, corticosteroids, diuretics, and sleep aids for insomnia.2 Some agents induce toxic myopathy that can lead to fatigue.11 If prescription medications are suspected to be the cause of fatigue or of CFS, patients should be asked to visit their prescriber for a full evaluation and consideration of alternative medications.


Drowsiness differs from fatigue in that it is a subjective feeling that sleep is needed. A patient may not be tired at all, but falls prey to an overwhelming need for sleep at an inappropriate time or in an inappropriate situation.12 

Counseling Patients With Drowsiness: It is normal to experience drowsiness after inadequate sleep because the patient has a “sleep debt.” However, some patients complain of abnormal sleepiness in spite of having obtained sufficient sleep the night before. The pharmacist can question these patients about their sleep patterns, how much they normally sleep, whether they snore, and whether their bed partner complains that they have episodes of breathing cessation during the night (sleep apnea). If the answers to these are unrevealing, the patient should be urged to visit a physician, who may conduct sleep studies to determine the root cause of this abnormal drowsiness. If the patient’s habits seem to demonstrate poor sleep, interrupted sleep, or inadequate sleep, he or she should be advised to adopt the principles of sleep hygiene. Patients may be asked whether they are depressed, anxious, stressed, or suffering general life boredom. A trial of antidepressants may help some of these patients. 

Causes of Drowsiness: Drowsiness may be caused by such widely varying etiologies as rotating shift work, sedating medications (e.g., antihistamines, antidepressants, pain medications), hypothyroidism, hypercalcemia, hyponatremia or hypernatremia, sleep apnea, and narcolepsy.12 

Nonprescription Products

In addition to helping patients uncover the sources of fatigue or drowsiness and referring them when appropriate, pharmacists can also recommend nonprescription treatment. The only medication found to be safe and effective for self-use when used as labeled is caffeine.2 Caffeine’s stimulant effect is well-known and is the primary reason for its ubiquitous recreational use. The stimulant dose approved as safe and effective is 100 to 200 mg, not more often than every 3 to 4 hours.2 Products include Vivarin and NoDoz, both containing 200 mg of caffeine per tablet/caplet. These products are not to be recommended for anyone under the age of 12 years. 

Labels will warn patients that these products contain approximately as much caffeine as a cup of coffee and that they should limit or stop caffeine use while taking them. Failure to do so could lead to nervousness, sleeplessness, irritability, and tachycardia. Of course, a cup of coffee can contain widely divergent amounts of caffeine, so the FDA warning is only an estimate for consumer use. Labels warn patients that these products are for occasional use only and that they will not substitute for sleep. Furthermore, if drowsiness or fatigue persists or recurs, patients should consult their physician. These products are not to be used if the patient is pregnant or breastfeeding. Their optimal use is for patients who are performing boring, repetitive tasks that lead to inattention (e.g., assembly-line work). They may also be useful to maintain maximal attentiveness during driving. 

Some patients are already consuming the recommended amount of caffeine in the form of coffee, tea, and soft drinks. Eight ounces of brewed coffee contains 135 mg of caffeine, and the same amount of brewed tea contains 50 mg.2 A 12-oz can of Coca-Cola or Pepsi-Cola contains 34 to 38 mg of caffeine, where the amount in other soft drinks may be as high as 55 mg/12 oz. A patient who drinks several cans of caffeinated soft drinks daily, along with a 20-oz cup of coffee from a popular coffee chain like Starbucks (480 mg of caffeine) is already consuming a considerable amount of stimulant.2 The 200 mg in a single NoDoz or Vivarin may not be enough to provide any benefit beyond the already high daily intake and could lead to unwanted effects. 


Fatigue and drowsiness are common medical conditions that can be caused by a host of serious disorders. Unless the cause is trivial and short-term, the patient should be referred to a physician for a full evaluation. 

Steps You Can Take

Before you take any medications for fatigue and drowsiness, you may wish to try some relatively easy solutions. You should not go to bed and arise at odd times or at different times each day. The best advice is to set a time for going to bed and also for arising and try to stick to them as much as possible. Everyone has experienced the “fun” of staying up till 4 am or later and then sleeping in until noon the next day. Even 8 hours of sleep cannot fool your body into normalcy, and you will feel the effects of your altered schedule the next day. In addition, strive to get at least 7 to 8 hours of sleep a night. Trying to get through the next day without adequate sleep leads to daytime drowsiness that is a major cause of fatal automobile accidents. Avoid stimulants such as caffeine or oral nasal decongestants (e.g., Sudafed) too close to bedtime, as the stimulant effect may not allow you to drop off to sleep at the right time, leaving you fatigued the following day. 

You should always eat a healthy, balanced diet and drink sufficient water to keep fully hydrated. Avoid all alcohol, nicotine, and drugs of abuse. If you habitually drink caffeine-containing soft drinks, coffee, or tea, try to reduce the amount or eliminate them completely to determine whether they are responsible for a tired feeling. You should also be aware of any medications you are taking that may cause drowsiness, such as antihistamines, antihypertensives, corticosteroids, diuretics, and sleep aids. 

One method to reduce fatigue is to reduce life stresses. It may be necessary to change from a job that causes severe stress to one that allows a more relaxing day of work. When you have spare time, do not spend it playing high-stress video games that require split-second timing and fast reflexes. Instead, go for a walk, read a book, or have a pleasant conversation with family and friends. If you are caught in a relationship that is fraught with problems, deal with them directly or end the relationship. 

Nonprescription Medications

The only pharmacy product proven safe and effective in helping fight fatigue and drowsiness is caffeine, found in such OTC products as Vivarin and NoDoz. Each caplet or tablet contains 200 mg of caffeine. Take one dose not more often than every 3 to 4 hours. These products are only safe for those aged 12 years and above. They are not a substitute for healthy sleep and should never be used to keep you awake all night. They should not be used if you are pregnant or breastfeeding without speaking to your physician first. 

Energy Drinks

Avoid the use of the popular energy drinks. Virtually all contain ingredients of unknown safety and effectiveness, such as herbs and dietary supplements. One contains such unproven ingredients as ginkgo, guarana, inositol, L-carnitine, ginseng, and milk thistle. Using products such as these is a risky gamble with your health, since they can have adverse effects and are not proven to provide a safe boost of energy. 

Remember, if you have questions, Consult Your Pharmacist. 


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