Minophylline 300 mg S.R. Tablets – Theophylline

Each tablet contains: Theophylline 300 mg in a patented controlled release system.

Pharmaceutical form

Controlled release tablets.

Pharmacological action

The exact mechanism of action of theophylline is unknown. Theophylline directly relaxes the smooth muscles of the bronchi and pulmonary blood vessels.

Theophylline increases the force of contraction of diaphragmatic muscles and may be capable of reducing fatigability and thereby improves contractility in patients with chronic obstructive airways disease.


Theophylline is rapidly and completely absorbed after oral administration, maximum plasma concentration is reached in 2 hrs. distributes freely into fat-free tissues & approximately 40% is bound to plasma protein and 90% of the dose metabolized in the liver, excreted by the kidneys (15% of the drug is excreted unchanged) .

It has also been demonstrated that twice- daily dosing produces minimal peak to trough variation and plasma theophylline levels can be maintained within the therapeutic range of 10-20 mcg/ml throughout the 12 hours dosing interval.


For the treatment and prophylaxis of bronchospasm associated with asthma, emphysema and chronic bronchitis. Also indicated for the treatment of cardiac asthma and left ventricular or congestive cardiac failure.

Dosage and administration

Adults: The usual maintenance dose is 300 or 400 mg 12-hourly following an initial week of therapy on 200 mg 12 hourly.

The Elderly:Initial week 200 mg/12 hours then the dose should be adjusted following the response to the initial week of therapy.

It may be appropriate to administer a large evening or morning dose in some patients, in order to achieve optimum therapeutic effect when symptoms are most severe e.g. at the time of the morning dip in lung function.

For patients not presently receiving theophylline whose night time or day time symptoms persist despite other therapy, a single evening or morning dose of Minophylline S.R. tablets may be added to their treatment regimen.

Children : 9 mg/kg twice daily some children with chronic asthma require and tolerate much higher dose (10-16 mg/kg twice daily).

Dose titration: Patients vary in their response to xanthines and it may be necessary to titrate dosages individually. Steady state of theophylline levels are generally attained 3 – 4 days after dose adjustment. If a satisfactory clinical response is not achieved, serum theophylline should be measured 6-8 hours after the last dose.

Based on serum theophylline assay results, dosage should be titrated as follows:

Peak serum Theophylline level Dosage adjustment to Nearest 200 mg.
<10 mcg/ml Increase total daily dose by half.
11-15 mcg/ml Increase total daily dose by 200 mg if symptoms persist.
16-20 mcg/ml No adjustment required
21-25 mcg/ml Decrease dose by 200 mg.
26-30 mcg/ml Miss next dose and decrease maintenance dose stepwise by 200 mg and check again.

It is advisable to re- check serum theophylline concentration after dose adjustment, when steady state is attained.

Side effects

The risk of side effects,usually associated with theophylline and xanthine derivatives such as nausea, gastric irritation, headache and CNS stimulation is significantly reduced when Minophylline S.R. tablet preparations are given.

Pregnancy and lactation

Theophylline should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Theophylline is excreted into breast milk and may cause irritability to the infants.

Precautions and warnings

Theophylline should be used with extreme caution in patients with active peptic ulcer disease, seizure disorders, cardiac arrhythmias.

Minophylline S.R. – FAQs

What is the drug Minophylline S.R. used for?

Minophylline S.R.  indicated for the treatment and prophylaxis of bronchospasm associated with asthma, emphysema and chronic bronchitis. It is also  indicated for the treatment of cardiac asthma and left ventricular or congestive cardiac failure.

What class of drugs is Minophylline S.R.?

Minophylline S.R. contains Theophylline, which belong to a drug class known as ” Xanthines ” used for OBSTRUCTIVE AIRWAY DISEASES.

What is Minophylline S.R. a steroid?

Minophylline S.R. is not a steroid, it belongs to a group of medicines called (Xanthine). It works by relaxing the smooth muscles of the bronchi and pulmonary blood vessels.

Why is Minophylline S.R. no longer used?

Due to its side effects that come with the higher doses, Minophylline S.R. is no longer widely prescribed.

What are the side effects of Minophylline S.R.?

Minophylline S.R. may cause the following side effects, and you should tell your doctor if any of these symptoms are aggravated or persist for a long time:

  • upset stomach – stomachache.
  • headache
  • Insomnia, difficulty sleeping.
  • Feeling uncomfortable and nervous.

Minophylline S.R. may cause serious side effects, and you should contact your doctor immediately if you experience any of the following symptoms:

  • Vomiting
  • Increased or rapid heart rate
  • Arrhythmia
  • convulsions
  • Skin rash.

Do doctors still prescribe Minophylline S.R.?

Nowadays, Minophylline S.R. is not widely prescribed , cause of its serious side effects, and its narrow therapeutic index

Who should not use Minophylline S.R.?

The patient should be alerted to refer to the doctor if you feel nausea, vomiting, persistent headache, insomnia, difficulty sleeping or lack of sleep, rapid heartbeat, diarrhea, or an increase in diuresis during treatment with Minophylline S.R., even if another cause is suspected. All the aforementioned symptoms indicate an increase in theophylline concentration in the blood and are considered signs of the onset of theophylline poisoning.

The patient must be informed of the need to contact the doctor if a new symptom occurs, especially persistent fever (unexplained high body temperature), or if  the patient feels a deterioration in respiratory functions, or if the patient begins to smoke cigarettes or begins to quit.

How long should I used  Minophylline S.R.?

The duration of treatment varies according to the targeted condition, and usually extends from two weeks to a month .

Does Minophylline S.R. affect heart rate?

Yes Minophylline S.R. affects the heart rate. It causes rapid  heart rate

How quickly does Minophylline S.R. work?

The effect of Minophylline S.R. begins within 20 minutes, the maximum effect is reached within two hours, and the effect of the pills lasts for a period ranging from 6 to 12 hours

Does Minophylline S.R. raise blood pressure?

Minophylline S.R. Affects heart rate, and in theory this effect can increase blood pressure.

List of Theophylline Controlled Released Tablets Products – MENA

  1. Uniphyllin Continus Tablets 300 or 400 mg- Mundi Pharma
  2. Theophylline 200 mg S.R. Tablets – Amriyia
  3. Quibron T/SR Tablets – 300 mg – BMS
  4. Minophylline 200 mg S.R. Tablets – Alexandria.
  5. Riaphyllin SR Tablets – 300 mg – Riyahd Pharma

Minophylline – AR information

Product reference code: R03DA04. Check product images on google.

Produced by: Alexandria Co. for Pharmaceuticals & Chemical Industries – Alex. -Egypt