Caffeine Pharmacology

Caffeine

About Caffeine

Xanthine alkaloid, Central stimulant and metabolic stimulant.

Mechanism of Action of Caffeine

Because caffeine is both water-soluble and lipid-soluble, it readily crosses the blood?brain barrier .Caffeine stimulates medullary, vagal, vasomotor, and respiratory centers, promoting bradycardia, vasoconstriction, and increased respiratory rate. Xanthines such as caffeine act as antagonists at adenosine-receptors within the plasma membrane of virtually every cell. As adenosine acts as an autocoid, inhibiting the release of neurotransmitters from presynaptic sites but augmenting the actions of norepinephrine or angiotensin, antagonism of adenosine receptors promotes neurotransmitter release. This explains the stimulatory effects of caffeine. Blockade of the adenosine A1 receptor in the heart leads to the accelerated, pronounced "pounding" of the heart upon caffeine intake.

Pharmacokinets of Caffeine

1.Absorption:Readily absorbed after oral or parenteral administration, C max is 5 to 25 mcg/mL; T max is 15 to 120 min.
2.Distribution:Widely distributed,Protein binding Low (25 to 36%).
3.Metabolism:Hepatic cytochrome P450 1A2
4.Elimination: Renal;In young infants, the elimination of caffeine is much slower than that in adults due to immature hepatic and/or renal function.

Onset of Action for Caffeine

N/A

Duration of Action for Caffeine

N/A

Half Life of Caffeine

3 to 7 hours in adults, 65 to 130 hours in neonates

Side Effects of Caffeine

1.Insomnia
2.Nervousness or anxiety
3.Irritability
4.Nausea
5.Headache

Contra-indications of Caffeine

1.Hyper sensitivity
2.Caffeine and sodium benzoate solution in pediatrics.

Special Precautions while taking Caffeine

1.Heart disease
2.Kidney disease
3.Liver disease
4.Stomach problems (e.g., peptic ulcers, necrotizing enterocolitis)
5.Seizures.

Pregnancy Related Information

Use with caution

Old Age Related Information

May be used

Breast Feeding Related Information

Use with caution

Children Related Information

Not recommended uder 12years of age

Indications for Caffeine

1.Orthostatic hypotension
2.Short term treatment of apnea of prematurity in infants
3.Fatigue and drowsiness
4.Analgesia
5.Respiratory depression.

Interactions for Caffeine

1.Aspirin, clozapine, theophylline :Plasma levels of these agents may be elevated by caffeine, increasing their pharmacologic effects and adverse reactions.
2.Cimetidine, disulfiram, fluoroquinolones, mexiletine, oral contraceptives :May increase caffeine levels, enhancing the effects.
3.Lithium :Plasma levels may be reduced by caffeine, decreasing the pharmacologic effect.
4.Phenytoin, smoking :May decrease caffeine levels.

Typical Dosage for Caffeine

1.Fatigue/Drowsiness :Oral:100 to 200 mg every 3 to 4 h as needed.
2.Apnea of Prematurity
Preterm infants Loading dose: (caffeine citrate) IV 20 mg/kg (1?mL/kg) over 30 min once.
Maintenance dose: (caffeine citrate) IV (over 10?min) or PO 5 mg/kg (0.25 mL/kg) every 24?h.

Schedule of Caffeine

N/A

Storage Requirements for Caffeine

Store caffeine at room temperature, between 59 and 86 degrees F (15 and 30 degrees C), in a tightly closed container. Store away from heat, moisture, and light.

Effects of Missed Dosage of Caffeine

N/A

Effects of Overdose of Caffeine

1.Get immediate medical attention
2.Symptoms of overdose may include agitation; anxiety; confusion; frequent urination; irregular or fast heartbeat; muscle twitching; ringing in the ears; seizures; stomach pain; trouble sleeping.

Home Delivery for Caffeine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including caffeine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for caffeine and other medicines and health products. Home delivery services for caffeine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take caffeine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for caffeine before they complete the sale. You can get this information while placing the order for caffeine with the pharmacy.

Caffeine is a generic medicine name and there are several brands available for it. Some of the brands for caffeine might be better known than caffeine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have caffeine in stock, you can ask for one of the branded alternatives for caffeine.