Caffeine; Caffeine and Sodium Benzoate Injection; Caffeine Citrate

• Competitively inhibits phosphodiesterase, the enzyme that degrades cyclic 3′,5′-adenosine monophosphate (AMP), increasing levels of intracellular cyclic AMP.120 a

• Stimulates all levels of the CNS.120 a Stimulates the cerebral cortex and produces a more rapid and clearer thought flow, wakefulness or arousal in fatigued patients; also improves psychomotor coordination.a

• Stimulates medullary vagal, vasomotor, and respiratory centers in slightly larger doses, promoting bradycardia, vasoconstriction, and increased respiratory rate.120 a

• Produces a positive inotropic effect on the myocardium and a positive chronotropic effect at the SA node, causing transient increases in heart rate, force of contraction, cardiac output, and heart work.115 120 a

• Constricts cerebral vasculature; also directly dilates peripheral blood vessels, decreasing peripheral vascular resistance.120 a Overall effect on heart rate and BP depends on whether CNS or peripheral effects predominate.120 a

• Stimulates voluntary skeletal muscle, increasing the force of contraction and decreasing muscular fatigue.120 a

• Stimulates gastric acid secretion from parietal cells.120 a

• Increases renal blood flow and GFR; decreases proximal tubular reabsorption of sodium and water, resulting in mild diuresis.120 a

Applies to caffeine / sodium benzoate: injection solution

Along with its needed effects, caffeine / sodium benzoate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking caffeine / sodium benzoate:

• Extra heartbeats
• fast, pounding, or irregular heartbeat or pulse
• trembling or shaking of the hands or feet

Get emergency help immediately if any of the following symptoms of overdose occur while taking caffeine / sodium benzoate:

• Chest pain or discomfort
• confusion
• confusion as to time, place, or person
• decreased urination
• dizziness
• dry mouth
• fainting
• fever
• hallucinations
• holding false beliefs that cannot be changed by fact
• increase in heart rate
• lightheadedness
• pounding or rapid pulse
• rapid breathing
• sleeplessness
• slow heartbeat
• sunken eyes
• thirst
• trouble sleeping
• unable to sleep
• unusual excitement, nervousness, or restlessness
• unusual tiredness or weakness
• wrinkled skin

Some side effects of caffeine / sodium benzoate may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Anxiety
• continuing ringing or buzzing or other unexplained noise in the ears
• headache
• hearing loss
• hyperventilation
• increased sensitivity to pain
• increased sensitivity to touch
• irritability
• restlessness
• shortness of breath
• tingling in the hands and feet
• trouble sleeping