Theophylline is a bronchodilator. It works by relaxing muscles of lungs and chest, and makes the lungs less sensitive to allergens. Counseling of drugs is one of the important responsibility of pharmacist. This article covers some useful parameters that must be communicated to the patients before dispensing the drugs.
Counseling for Indications
Different drugs have different therapeutic uses and sometime single drug is used for the treatment of multiple infections. It is the duty of pharmacist to discuss therapeutic uses of each drug that is being dispensed to the patient. Theophylline is commonly used for the treatment and management of asthma, COPD and bronchitis. Some precise indications of this drug are given bleow;
- Prevention or treatment of reversible bronchospasm associated with asthma or chronic obstructive pulmonary disease (COPD).
- Treatment of apnea and bradycardia of prematurity and reduction of essential tremor.
Counseling for side effects:
Every drug has some specific side effects that can be reversible or irreversible. The pharmacist should communicate all the possible adverse event or side effects that a patient can suffer after taking that drug. Counsel the patient that if you suffer any of the side effects mentioned below than consult your doctor immediately and stop intake of drug.
Some common side effects of theophylline are given below.
- Seizure (convulsions);
- Worsening your current condition;
- Severe or continuous nausea and;
- Coughing up blood or vomit that looks like coffee grounds;
- Feeling restless, irritable, nervous, or jittery.
- Tremors; or
- Urinating more than usual.
Counseling for Dose:
Pharmacist should know that theophylline is a potent drug and little variation in its dose will cause serious consequences that a patient has to bear. So counsel the patients that do not increase the dose of this drug from the recommended dose as prescribed by the physician.
5 mg/kg loading dose (patient not receiving theophylline or aminophylline).
- Healthy Non Smoking Adult: 10 mg/kg/day. Do not exceed 900 mg/day.
- Healthy Adult Smoker: 16 mg/kg/day.
- Patient with congestive heart failure: 5 mg/kg/day. Do not exceed 400 mg/day.
- Seek emergency medical help if you think you have taken too much quantity (overdose) of this medicine. Some sign and symptoms of its overdose may include nausea, vomiting, insomnia, tremors, restlessness, uneven heartbeats, and seizure (convulsions). Seizures caused by a theophylline overdose can sometimes cause death or permanent brain damage.
Counseling for Administration:
- Sometime sustained release formulations of drugs are encouraged to take on an empty stomach to prevent rapid release of drug.
- Theophylline can be swallowed with fluid or swallow enclosed granules with soft food like yoghurt (suggested by British National Formulary)
- Counsel the patient that do not crush or chew if you are taking a sustained release formulation of theophylline
- Counsel the patient that theophylline is a potent drug and therapeutic drug monitoring (TDM) is recommended for this drug. So its plasma level should be in the range of 7 to 20 mcg/ml. Some patients may suffer toxic effects at the upper limit of this range.
Counseling for Pregnancy:
Theophylline has been assigned to pregnancy category C by the FDA. It is only recommended for use under the close supervision of physician during pregnancy when there are no alternatives and benefit outweighs the risk.
Counseling for Drug Interaction:
- Counsel the patient that co-administration of certain drugs will either increase the risk of therapeutic failure or toxicity. So avoid the use of such drugs;
- Tell the patient that if you are suffering from hypertension and your doctor has prescribed beta blocker like blokium (atenolol) then do not use this beta blocker as it will cause bronchoconstriction and will worsen the pre-existing asthma or COPD condition. Some other anti-hypertensive therapies should be preferred in such conditions. ;
- Commonly used NSAIDs like aspirin should not be used as it can worse the pre-existing asthmatic or COPD condition. So discourage the patient regarding the use of such drug without consulting the physician. A list of some common drugs has been mentioned here that could possibly interfere with the effects of theophylline. So a pharmacist should know and counsel timely regarding the use of such drugs.
Drugs which increase the theophylline level are:
Allopurinol, nonselective beta-blockers, calcium channel blockers, cimetidine, oral contraceptives, corticosteroids, disulfiram, ephedrine, influenza virus vaccine, interferon, macrolide antibiotics (eg, erythromycin), mexiletine, quinolone antibiotics (eg, ciprofloxacin), thyroid hormones
Drugs which decrease its effect are;
Aminoglutethimide, barbiturates, hydantoins, ketoconazole, rifampin, smoking (cigarettes and marijuana), sulfinpyrazone, sympathomimetics.
Counseling for Food Interactions:
Advise the patients that do not drink grapefruit juice as it is a potent inhibitor of P450 system and will inhibit the metabolism of theophylline. As a result patient will suffer severe side effects including tremors and etc.
Counselling for Contraindications:
Counsel the patient that if you have hypersensitivity to theophylline or suffering from epilepsy or any seizure disorder, then does not use this drug as its use is contraindicated in such conditions.
Counseling for Precautions:
Use of theophylline should be done with great caution if you have any of the following problems
- Cardiac disease;
- Hepatic impairment;
- Breast feeding.
Counseling for Storage:
- Counsel the patients that store this medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing;
- Keep out of the reach of children;
- Do not keep outdated medicine or medicine no longer needed.
Important Note for Pharmacist:
The absorption rate of theophylline from modified release preparation among different brands can vary. So if physician has prescribed a modified release oral theophylline without mentioning the brand then it is the responsibility of pharmacist to consult with physician regarding the selection of a suitable brand according to the guidelines given by Council of the Royal Pharmaceutical Society of Great Britain.
- Tatro DS, Borgsdorf LR. A to z drug facts. Facts & Comparisons, 2003.
- Committee JF, Britain RPSoG. British National Formulary (BNF) 64. Pharmaceutical Press, 2012.
- Knoben JE, Anderson PO, Watanabe AS. Handbook of clinical drug data. Drug Intelligence Publications Hamilton, IL, 1988.
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