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Stay Awake Side Effects

Generic Name: caffeine

Note: This page contains side effects data for the generic drug caffeine. It is possible that some of the dosage forms included below may not apply to the brand name Stay Awake.

For the Consumer

Applies to caffeine: oral capsule, oral capsule extended release, oral packet, oral powder for suspension, oral solution, oral tablet, oral tablet chewable, oral tablet enteric coated, oral tablet extended release

Other dosage forms:

As well as its needed effects, caffeine (the active ingredient contained in Stay Awake) may cause unwanted side effects that require medical attention.

If any of the following side effects occur while taking caffeine, check with your doctor immediately:

More common
  • Feeding intolerance
Less common
  • Agitation
  • black, tarry stools
  • blood in the stools or urine
  • bruising
  • burning feeling or tenderness in the stomach
  • chills
  • coma
  • confusion
  • coughing or vomiting blood
  • decreased urine output
  • depression
  • dizziness
  • fainting
  • fast heartbeat
  • fever
  • headache
  • hostility
  • indigestion
  • irritability
  • lethargy
  • lightheadedness
  • muscle twitching
  • nausea
  • persistent bleeding
  • rapid, shallow breathing
  • rapid weight gain
  • rash
  • seizures
  • severe stomach pain
  • stomach upset
  • stupor
  • swelling of the face, ankles, or hands
  • trouble breathing
  • unusual tiredness or weakness
  • vomiting
  • vomiting of blood or material that looks like coffee grounds

If any of the following symptoms of overdose occur while taking caffeine, get emergency help immediately:

Symptoms of overdose
  • Irritability
  • nervousness
  • rapid heartbeat
  • trouble sleeping

Some caffeine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common
  • Rash
Less common
  • Dry skin

For Healthcare Professionals

Applies to caffeine: compounding powder, intravenous solution, oral gum, oral liquid, oral tablet, oral tablet dispersible, oral tablet extended release


In general, consumption of higher doses of caffeine (the active ingredient contained in Stay Awake) (less than 600 mg/day) has been reported to have lead to caffeinism. Caffeinism is a syndrome characterized by anxiety, restlessness, and sleep disorders (similar to anxiety states). It has also been reported that chronic, heavy caffeine ingestion may be associated with depression. Caffeine may cause anxiety and panic in panic disorder patients and may aggravate premenstrual syndrome (PMS).

Two studies have shown that caffeine consumption is associated with a lower serum uric acid level and a lower risk of incident gout.[Ref]


Gastrointestinal side effects associated with caffeine (the active ingredient contained in Stay Awake) citrate have included necrotizing enterocolitis in infants. Increased gastric aspirate and gastrointestinal intolerance have been reported rarely with caffeine products.[Ref]

In clinical trials of caffeine citrate, six cases of necrotizing enterocolitis (3 fatal) were reported among 85 infants exposed to caffeine citrate injection, however, causality has not been established.[Ref]


In one study of 634 women with fibrocystic breast disease (compared to 1066 women without the disease), the occurrence of fibrocystic breast disease was positively associated with average daily consumption of caffeine (the active ingredient contained in Stay Awake) Women who consumed 31 to 250 mg/day of caffeine were reported to have a 1.5 times increase in odds to have the disease. Women who consumed over 500 mg/day of caffeine were reported to have a 2.3 times increase in odds.[Ref]

Other side effects associated with caffeine consumption have included fibrocystic breast disease in women.

One study has reported that while favorable subjective and performance-enhancing stimulant effects occur at low to intermediate caffeine doses, the unfavorable subjective and somatic effects, as well as performance disruption from high doses of caffeine may intrinsically limit the doses of caffeine used in the general population.[Ref]


Psychiatric side effects have included confusion and psychotic symptoms.[Ref]


Cardiovascular side effects associated with caffeine (the active ingredient contained in Stay Awake) products have rarely included tachycardia, increased left ventricular output, and increased stroke volume.[Ref]

One study (n=77) reported increased blood pressure following caffeine intake (3.3 mg/kg) of approximately 4.5 mmHg in premenopausal women and 4.1 mmHg in men. Although men and women showed similar responses in blood pressure following consumption of a dietary dose of caffeine the hemodynamic mechanisms facilitating this change are different. Premenopausal women showed an increase in cardiac output whereas men showed increased vascular resistance.

One small study (n=12) reports caffeine to exert an acute unfavorable effect on aortic stiffness in treated hypertensive patients. This effect peaked approximately 60 minutes following administration of caffeine 250 mg orally, lasted a minimum duration of approximately 3 hours, and then decreased gradually.[Ref]


Endocrine side effects associated with caffeine (the active ingredient contained in Stay Awake) products have rarely included alterations in serum glucose such as hypoglycemia and hyperglycemia.[Ref]

Several studies report a decrease in insulin sensitivity in individuals following caffeine consumption. The mechanism leading to this effect is unknown but may be related to elevated serum epinephrine levels.

A few studies report a possible decreased risk of type 2 diabetes mellitus in individuals who consume coffee.[Ref]

Nervous system

Nervous system side effects associated with caffeine (the active ingredient contained in Stay Awake) consumption have included central nervous system stimulation such as irritability, restlessness, and jitteriness.[Ref]


Renal side effects associated with caffeine (the active ingredient contained in Stay Awake) consumption have included increased urine flow rate, creatinine clearance, and sodium and calcium excretion.[Ref]


Genitourinary side effects associated with caffeine (the active ingredient contained in Stay Awake) products include urinary incontinence (UI) in men and women.[Ref]


1. Clementz GL, Dailey JW "Psychotropic effects of caffeine." Am Fam Physician 37 (1988): 167-72

2. Choi HK, Willett W, Curhan G "Coffee consumption and risk of incident gout in men: A prospective study." Arthritis Rheum 56 (2007): 2049-2055

3. Sawynok J "Pharmacological rationale for the clinical use of caffeine." Drugs 49 (1995): 37-50

4. Choi HK, Curhan G "Coffee, tea, and caffeine consumption and serum uric acid level: The third national health and nutrition examination survey." Arthritis Rheum 57 (2007): 816-821

5. "Product Information. Cafcit (caffeine)" Roxane Laboratories Inc, Columbus, OH.

6. Boyle CA, Berkowitz GS, LiVolsi VA, Ort S, Merino MJ, White C, Kelsey JL "Caffeine consumption and fibrocystic breast disease: a case-control epidemiologic study." J Natl Cancer Inst 72 (1984): 1015-9

7. Pfeiffer M, Stanojevic S, Feuchtinger T, et al. "Rituximab mediates in vitro antileukemic activity in pediatric patients after allogeneic transplantation." Bone Marrow Transplant (2005):

8. Sondermeijer H, van Marle A, Kamen P, Krum H "Acute effects of caffeine on heart rate variability." Am J Cardiol 90 (2002): 906

9. Hartley TR, Lovallo WR, Whitsett TL "Cardiovascular effects of caffeine in men and women." Am J Cardiol 93 (2004): 1022-6

10. Vlachopoulos C, Hirata K, Stefanadis C, Toutouzas P, O'Rourke MF "Caffeine increases aortic stiffness in hypertensive patients." Am J Hypertens 16 (2003): 63-6

11. Thong FS, Derave W, Kiens B, et al. "Caffeine-induced impairment of insulin action but not insulin signaling in human skeletal muscle is reduced by exercise." Diabetes 51 (2002): 583-90

12. Watson J, Deary I, Kerr D "Central and peripheral effects of sustained caffeine use: tolerance is incomplete." Br J Clin Pharmacol 54 (2002): 400-6

13. Biaggioni I, Davis SN "Caffeine: a cause of insulin resistance?" Diabetes Care 25 (2002): 399-400

14. "Summaries for patients. Coffee drinkers at lower risk for type 2 diabetes." Ann Intern Med 140 (2004): I17

15. Keijzers GB, De Galan BE, Tack CJ, Smits P "Caffeine can decrease insulin sensitivity in humans." Diabetes Care 25 (2002): 364-9

16. Davis NJ, Vaughan CP, Johnson TM 2nd, et al. "Caffeine Intake and its association with urinary incontinence in US men: Results from National Health and Nutritional Examination Surveys (NHANES) 2005-06 and 2007-08." J Urol 189 (2013): 2170-4

It is possible that some side effects of Stay Awake may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.