Some commonly used brand names are:

In the U.S.—

In Canada—

• Analgesia adjunct --Caffeine
• Respiratory stimulant adjunct --Caffeine; Caffeine, Citrated
• Stimulant, central nervous system --Caffeine; Caffeine and Sodium Benzoate; Caffeine, Citrated

Caffeine (KAF-feen) belongs to the group of medicines called central nervous system (CNS) stimulants. It is used to help restore mental alertness when unusual tiredness or weakness or drowsiness occurs. Caffeine's use as an alertness aid should be only occasional. It is not intended to replace sleep and should not be used regularly for this purpose.

Caffeine is also used in combination with ergotamine (for treatment of migraine and cluster headaches) or with certain pain relievers, such as aspirin or aspirin and acetaminophen. When used in this way, caffeine may increase the effectiveness of the other medicines. Caffeine is sometimes used in combination with an antihistamine to overcome the drowsiness caused by the antihistamine.

Citrated caffeine is used to treat breathing problems in premature babies.

Caffeine may also be used for other conditions as determined by your doctor.

Caffeine is present in coffee, tea, soft drinks, cocoa, chocolate, and kola nuts.

Caffeine powder and tablets are available without a prescription; however, your health care professional may have special instructions on its proper use. Citrated caffeine and caffeine and sodium benzoate are to be administered only by or under the supervision of your doctor. Caffeine is available in the following dosage forms:

Oral
• Caffeine
  • Powder (U.S.)
  • Tablets (U.S. and Canada)
• Citrated caffeine
  • Oral solution (U.S.)

Parenteral
• Citrated caffeine
  • Injection (U.S.)
• Caffeine and sodium benzoate
  • Injection (U.S.)

If you are taking this medicine without a prescription, carefully read and follow any precautions on the label. For caffeine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reactions to aminophylline, caffeine, dyphylline, oxtriphylline, theobromine (also found in cocoa or chocolate), or theophylline. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies in humans have shown that caffeine may cause miscarriage or may slow the growth of a developing fetus when given in doses greater than 300 mg (an amount equal to three cups of coffee) a day. In addition, use of large amounts of caffeine by the mother during pregnancy may cause problems with the heart rhythm of the fetus. Therefore, it is recommended that pregnant women consume less than 300 mg of caffeine a day. Studies in animals have shown that caffeine causes birth defects when given in very large doses (amounts equal to 12 to 24 cups of coffee a day) and problems with bone growth when given in smaller doses.

Breast-feeding—Caffeine passes into breast milk in small amounts and may build up in the nursing baby. Studies have shown that babies may appear jittery and have trouble in sleeping when their mothers drink large amounts of caffeine-containing beverages.

Children—With the exception of infants, there is no specific information comparing use of caffeine in children with use in other age groups. However, this medicine is not expected to cause different side effects or problems in children than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of caffeine in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking caffeine, it is especially important that your health care professional know if you are taking any of the following:

• Amantadine (e.g., Symmetrel) or
• Amphetamines (e.g., Desoxyn, Dexedrine) or
• Appetite suppressants (diet pills) or
• Bupropion (e.g., Wellbutrin) or
• Chlophedianol (e.g., Ulone) or
• Cocaine or
• Fluoxetine (e.g., Prozac) or
• Medicine for asthma or other breathing problems or
• Medicine for colds, sinus problems, hay fever or other allergies (including nose drops or sprays) or
• Methylphenidate (e.g., Ritalin) or
• Nabilone (e.g., Cesamet) or
• Other medicines or beverages containing caffeine or
• Paroxetine (e.g., Paxil) or
• Pemoline (e.g., Cylert) or
• Sertraline (e.g., Zoloft)—Using these medicines with caffeine may increase the CNS-stimulant effects, such as nervousness, irritability, or trouble in sleeping, or possibly cause convulsions (seizures) or changes in the rhythm of your heart

• Monoamine oxidase (MAO) inhibitors (furazolidone [e.g., Furoxone], isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate])—Taking large amounts of caffeine while you are taking or within 2 weeks of taking MAO inhibitors may cause extremely high blood pressure or dangerous changes in the rhythm of your heart; taking small amounts of caffeine may cause mild high blood pressure and fast heartbeat

• Agoraphobia (fear of being in open places) or
• Anxiety or
• Convulsions (seizures) (in newborn babies) or
• Heart disease, severe or
• High blood pressure or
• Panic attacks or
• Trouble in sleeping—Caffeine may make the condition worse

• Liver disease—Higher blood levels of caffeine may result, increasing the chance of side effects

Take caffeine in powder or tablet form only as directed. Do not take more of it, do not take it more often, and do not take it for a longer time than directed. Taking too much of this medicine may increase the chance of side effects. It may also become habit-forming.

For patients taking the powder form of this medicine: Each packet contains one dose of medicine. The contents of the packet may be stirred into water or other liquid and drunk. Or, the powder may be placed on the tongue and washed down with water or other liquid drink.

For patients taking the oral solution form of this medicine: Throw away any unused portion of the medicine left in the single-use vial (bottle). Follow the manufacturer's instruction for use.

If you think this medicine is not working properly after you have taken it for a long time, do not increase the dose. To do so may increase the chance of side effects.

Dosing—

The dose of caffeine will be different for different patients. Follow the directions on the label.

• For unusual tiredness or weakness, or drowsiness:
  • For oral dosage form (powder):
    • Adults and children 12 years of age and older—The usual dose is 200 milligrams (mg) of caffeine (1 packet) repeated no sooner than every three or four hours. You should not take more than 1600 mg in twenty-four hours.
    • Children up to 12 years of age—Use is not recommended.
  • For oral dosage form (tablets):
    • Adults and children 12 years of age and older—The usual dose is 100 to 200 mg of caffeine repeated no sooner than every three or four hours. You should not take more than 1000 mg in twenty-four hours.
    • Children up to 12 years of age—Use is not recommended.
• For breathing problems in premature babies:
  • For oral dosage form (oral solution):
    • Newborn babies—At first, the dose is 20 mg (1 milliliter [mL]) per kilogram (kg) (9.1 mg per pound) of body weight given one time. Then, the dose is 5 mg (0.25 mL) per kg (2.3 mg per pound) of body weight given once a day.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Caffeine powder and tablets are for occasional use only. They are not intended to replace sleep and should not be used regularly for this purpose. If unusual tiredness or weakness or drowsiness continues or returns often, check with your doctor.

Before you have any medical tests, tell the doctor in charge that you are taking this medicine. The results of some tests on the heart may be affected by this medicine.

The recommended dose of this medicine contains about the same amount of caffeine as a cup of coffee. Do not drink large amounts of caffeine-containing coffee, tea, or soft drinks while you are taking this medicine. Also, do not take large amounts of other medicines that contain caffeine. To do so may cause unwanted effects.

The amount of caffeine in some common foods and beverages is as follows:

• Coffee, brewed—40 to 180 milligrams (mg) per cup.
• Coffee, instant—30 to 120 mg per cup.
• Coffee, decaffeinated—3 to 5 mg per cup.
• Tea, brewed American—20 to 90 mg per cup.
• Tea, brewed imported—25 to 110 mg per cup.
• Tea, instant—28 mg per cup.
• Tea, canned iced—22 to 36 mg per 12 ounces.
• Cola and other soft drinks, caffeine-containing—36 to 90 mg per 12 ounces.
• Cola and other soft drinks, decaffeinated—0 mg per 12 ounces.
• Cocoa—4 mg per cup.
• Chocolate, milk—3 to 6 mg per ounce.
• Chocolate, bittersweet—25 mg per ounce.

Caffeine may cause nervousness or irritability, trouble in sleeping, dizziness, or a fast or pounding heartbeat. If these effects occur, discontinue the use of caffeine-containing beverages and medicines, and do not eat large amounts of chocolate-containing products.

To prevent trouble in sleeping, do not take caffeine-containing beverages or medicines too close to bedtime.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, they may be more likely to occur if caffeine is taken in large doses or more often than recommended. If they do occur, they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Diarrhea;  dizziness;  fast heartbeat;  hyperglycemia, including blurred vision, drowsiness, dry mouth, flushed dry skin, fruit-like breath odor, increased urination, ketones in urine, loss of appetite, nausea, stomachache, tiredness, troubled breathing, unusual thirst, or vomiting (in newborn babies);  hypoglycemia, including anxious feeling, blurred vision, cold sweats, confusion, cool pale skin, drowsiness, excessive hunger, fast heartbeat, nausea, nervousness, restless sleep, shakiness, or unusual tiredness or weakness (in newborn babies);  irritability, nervousness, or severe jitters (in newborn babies);  nausea (severe) ;  tremors;  trouble in sleeping ;  vomiting 
  
  

• Rare
  • Abdominal or stomach bloating;  dehydration ;  diarrhea (bloody);  unusual tiredness or weakness 
  
  

• Symptoms of overdose
  • Abdominal or stomach pain;  agitation, anxiety, excitement, or restlessness;  confusion or delirium;  convulsions (seizures)—in acute overdose ;  dehydration;  faster breathing rate;  fast or irregular heartbeat;  fever;  frequent urination;  headache;  increased sensitivity to touch or pain ;  irritability;  muscle trembling or twitching;  nausea and vomiting, sometimes with blood;  overextending the body with head and heels bent backward and body bowed forward;  painful, swollen abdomen or vomiting (in newborn babies);  ringing or other sounds in ears;  seeing flashes of “zig-zag” lights;  trouble in sleeping;  whole-body tremors (in newborn babies) 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Nausea (mild);  nervousness or jitters (mild) 
  
  

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this time, check with your doctor if you notice any of the following side effects:

• More common
  • Anxiety;  dizziness;  headache;  irritability;  muscle tension;  nausea;  nervousness;  stuffy nose;  unusual tiredness 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, caffeine is used in certain patients with the following medical conditions:

• Postoperative infant apnea (breathing problems after surgery in young babies)
• Psychiatric disorders requiring electroconvulsive or shock therapy (ECT)

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for these uses.