• Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

What is caffeine tablets-oral, and how does it work (mechanism of action)?

Caffeine acts as a stimulant of the nervous system by inhibiting the enzyme phosphodiesterase, just like theophylline and aminophylline. Inhibiting this enzyme leads to increased formation of the proteins which causes release of stimulating chemical signals known as neurotransmitters. These neurotransmitters bind to various sites in the body, including the brain, heart, and muscles to cause a stimulant effect.

What brand names are available for caffeine tablets-oral?

Enerjets, No Doz, Vivarin

Is caffeine tablets-oral available as a generic drug?


Do I need a prescription for caffeine tablets-oral?


What are the side effects of caffeine tablets-oral?

Side effects associated with caffeine supplements include irregular heartbeat, chest pain, flushing, palpitations, rapid heartbeat, agitation, dizziness, hallucinations, headache, insomnia, irritability, psychosis, restlessness, rash, increased pressure in the eye, and frequent urination.

What is the dosage for caffeine tablets-oral?

100 to 200 mg every 3 to 4 hours as needed no later than 6 hours before bedtime.

Which drugs or supplements interact with caffeine tablets-oral?

Combining caffeine with other stimulating agents, such as methylphenidate (Ritalin, Ritalin SR, Ritalin LA, Concerta, Methylin, Methylin ER, Metadate CD, Metadate ER), should be done with caution. This combination may cause increased side effects including rapid heartbeat, high blood pressure, hallucinations, tremor, and anxiety. Other dietary sources of caffeine, such as tea, add to the effect. Caffeine should be used with caution with adenosine, as the effects of adenosine may be diminished. Linezolid, phenelzine, selegiline, and tranylcypromine combined with caffeine increases the risk of high blood pressure. Consider alternatives when combining caffeine and vemurafenib and Stiripentol as caffeine concentrations may be increased.

Is caffeine tablets-oral safe to take if I'm pregnant or breastfeeding?

Category C; usual dietary exposure to caffeine is unlikely to cause congenital malformations, however studies show conflicting results about adverse events. Concentrations in the mother are similar to those found in the fetus. Daily intake should be no more than 200 mg.

Caffeine enters the breast milk, and, therefore should be used cautiously by nursing mothers.

What else should I know about caffeine tablets-oral?

What preparations of caffeine tablets-oral are available?

Tablets: 200 mg; Lozenge: 75mg

How should I keep caffeine tablets-oral stored?

Caffeine should be stored at room temperature, between 20 C to 25 C (68 F to 77 F).

Health Solutions From Our Sponsors

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

REFERENCE: Medicines in my Home: Caffeine and Your Body.