Theophylline Pharmacology

Theophylline

About Theophylline
Bronchodilator, a methylxanthine derivative, Anti asthma, in COPD.
Mechanism of Action of Theophylline
It inhibit phosphodiesterase enzyme which degrades cyclic nucleotides intracellularly and it results the cyclic AMP accumulation in the cell. This cause bronchodialatation, cardiac stimulation and vasodilatation. This drug release calcium from sarcoplasmic reticulam, especially in cardiac muscles and results increased cardiac muscle contraction. This drug also blocks adenosine receptors (adenosine acts as a local mediator in CNS & CVS and other organs- which contracts smooth muscles, especially in bronchi, blood vessels etc). This results bronchodialatation and vasodialatation.
Pharmacokinets of Theophylline
Absorption- Well absorbed after oral administration. Rapidly and well absorbed after intravenous administration.
Distribution- Widely distributed in the body. 40% bound to the plasma proteins.
Metabolism- Metabolized in the liver by demethylation and oxidation. 1-methyluric acid is its metabolite.
Excretion- Excreted through urine.
Onset of Action for Theophylline
15 to 60 min. after oral administration and 15 minutes after intravenous administration.
Duration of Action for Theophylline
N/A
Half Life of Theophylline
Its plasma half life is 8 hrs
Side Effects of Theophylline
1. Upset stomach
2. Stomach pain
3. Diarrhea
4. Headache
5. Restlessness
6. Insomnia
7. Irritability
8. Vomiting
9. Increased or rapid heart rate
10. Irregular heartbeat
11. Seizures
12. Skin rash

Contra-indications of Theophylline
1. Hypersensitivity to the drug
2. Peptic ulcer
3. Underlying seizure disorders

Special Precautions while taking Theophylline
1. Cardiac disease
2. Hypertension
3. Hyperthyroidism
4. Hepatic impairment
5. Fever
Pregnancy Related Information
Use with caution
Old Age Related Information
Use with caution
Breast Feeding Related Information
Use with caution
Children Related Information
Use with caution
Indications for Theophylline
1. Asthma
2. Chronic obstructive pulmonary disease
3. Chronic bronchitis
4. Emphysema
5. It can be used in premature infants who stop breathing

Interactions for Theophylline
Benzodiazepines: Sedative effects may be antagonized.
Beta agonists: Additive effect.
Halothane: Catecholamine induced arrhythmias may occur.
Tetracyclines: Theophylline adverse reaction may be enhanced.
Food: Theophylline elimination is increased by a low carbohydrate, high protein diet.
Typical Dosage for Theophylline
Adults:
Long term management of chronic bronchospasm: 300 to 1000 mg daily in divided doses in every 6 to 8 hrs or 175 to 500 mg every 12 hrs for modified release preparations.
Bronchospasm-
Adults-
5mg/kg body weight every 6 to 8 hrs.
Children- 5 mg/kg every 4 to 6 hrs.

Neonatal apnoea of prematurity-
Child-
More than 24days - 5mg/kg as maintenance dose and 1.5mg/kg every 12 hrs as loading dose.
Less than 24 days- 1mg/kg every 12 hrs.
Intravenous- Management of severe bronchospasm-
Adult- 4 to 5 mg/kg as loading dose over 20 to 30 minutes.
0.4 mg/kg/hr as maintenance dose.
Children- 4 to 5 mg/kg as loading dose over 20 to 30 minutes.
0.8mg/kg/hr as maintenance dose.

Schedule of Theophylline
N/A
Storage Requirements for Theophylline
Store it at room temperature and away from excess heat and moisture.
Effects of Missed Dosage of Theophylline
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Theophylline
Give symptomatic and supportive treatment. Induce emesis except in convulsive patient. Administer activated charcoal or cathartics to prevent further absorption of the drug.

Home Delivery for Theophylline in Your City

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

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 theophylline and other medicines and health products. Home delivery services for theophylline 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 theophylline 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 theophylline before they complete the sale. You can get this information while placing the order for theophylline with the pharmacy.

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