Theophylline; Uses, Dosage, Side effects, Drug Interactions

Theophylline, Theophylline; Uses, Dosage, Side effects, Drug Interactions, Rx Harun
If this article seems to be helpful, please rate/review us & share to others









User Review


5
(3 votes)


Theophylline is a natural alkaloid derivative of xanthine isolated from the plants Camellia sinensis and Coffea arabica. Theophylline appears to inhibit phosphodiesterase and prostaglandin production, regulate calcium flux and intracellular calcium distribution, and antagonize adenosine. Physiologically, this agent relaxes bronchial smooth muscle, produces vasodilation (except in cerebral vessels), stimulates the CNS, stimulates cardiac muscle, induces diuresis, and increases gastric acid secretion; it may also suppress inflammation and improve contractility of the diaphragm.

A methylxanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Mechanistically, theophylline acts as a phosphodiesterase inhibitor, adenosine receptor blocker, and histone deacetylase activator. As a member of the xanthine family, it bears structural and pharmacological similarity to theobromine and caffeine, and is readily found in nature, and is present in tea (Camellia sinensis) and cocoa (Theobroma cacao). A small amount of theophylline is one of the products of caffeine metabolic processing in the liver.

Mechanism of action of theophylline

Theophylline relaxes the smooth muscle of the bronchial airways and pulmonary blood vessels and reduces airway responsiveness to histamine, methacholine, adenosine, and allergen. Theophylline competitively inhibits type III and type IV phosphodiesterase (PDE), the enzyme responsible for breaking down cyclic AMP in smooth muscle cells, possibly resulting in bronchodilation. Theophylline also binds to the adenosine A2B receptor and blocks adenosine mediated bronchoconstriction. In inflammatory states, theophylline activates histone deacetylase to prevent transcription of inflammatory genes that require the acetylation of histones for transcription to begin.

You Can Also Like   Abdominal Pain; Causes, Symptom, Diagnosis, Treatment

Indications of theophylline

Contra Indications of theophylline

Dosages of theophylline

Strengths: 100 mg; 200 mg; 400 mg/24 hours; 600 mg/24 hours; 125 mg; 300 mg; 450 mg;

Asthma – Acute

  • Loading dose: 5 mg/kg loading dose (patient not receiving theophylline or aminophylline).

Maintenance dose

  • Otherwise Healthy Nonsmoking Adult: 10 mg/kg/day. Do not exceed 900 mg/day.
  • Otherwise Healthy Adult Smoker: 16 mg/kg/day.

Asthma – Maintenance

Loading dose

  • 5 mg/kg loading dose (patient not receiving theophylline or aminophylline).

Maintenance dose

  • Otherwise Healthy Nonsmoking Adult: 10 mg/kg/day. Do not exceed 900 mg/day.
  • Otherwise Healthy Adult Smoker: 16 mg/kg/day.
  • Patient with congestive heart failure or cor pulmonale: 5 mg/kg/day. Do not exceed 400 mg/day.

Pediatric Dose for Asthma – Acute

Loading dose

  • If no theophylline has been administered in the previous 24 hours: 5 mg/kg loading dose to achieve a serum concentration of about 10 mcg/mL;

Maintenance dose

  • less than 42 days: 4 mg/kg/day orally.
  • 42 days to 181 days: 10 mg/kg/day orally. Alternate dosing: [(0.2 x age in weeks) + 5] x kg = 24 hour oral dose in milligrams.
  • 6 months less than 12 months: 12 to 18 mg/kg/day. Alternate dosing: [(0.2 x age in weeks) + 5] x kg = 24 hour oral dose in milligrams.
  • 1 year to 8 years: 20 to 24 mg/kg/day.
  • 9 years to 11 years: 16 mg/kg/day.
  • 12 years to 15 years: 13 mg/kg/day.
  • 16 years or older: 10 mg/kg/day. Do not exceed 900 mg/day.
You Can Also Like   Alpha Blockers; Types, Uses, Contra Indications, Side Effects, Interactions

Pediatric Dose for Apnea of Prematurity

Manufacturer recommendations

  • Loading dose: 4.6 mg/kg/dose

Maintenance

  • Premature neonates: Post natal age less than 24 days: 1 mg/kg/dose every 12 hours
  • Premature neonates: Post natal age 24 or more days: 1.5 mg/kg/dose every 12 hours
  • Full term infants: Total daily dose (mg) = [(0.2 x age in weeks) +5] x (weight in kg); divide dose into 3 equal amounts and administer at 8 hour intervals

Side Effects of theophylline

The most common

Common

Less common

Drug Interactions of theophylline

Theophylline may interact with following drugs,suppliment & may change the efficacy of drugs

You Can Also Like   Deep Vein Thrombosis; Symptoms, Diagnosis, Treatment

Pregnancy & Lactation of theophylline

FDA Pregnancy Category B

Pregnancy

This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding

It is not known if orciprenaline passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

References

 

Theophylline, Theophylline; Uses, Dosage, Side effects, Drug Interactions, Rx Harun

Theophylline, Theophylline; Uses, Dosage, Side effects, Drug Interactions, Rx Harun

Sharing to Spread to the World

Leave a Reply

Your email address will not be published.