The truism “the harder you look, the more you find” is best illustrated in the area of adverse drug reactions. Life-threatening emergencies like hemorrhage, hypoglycemic coma, cardiac arrhythmias, convulsions, or a hypertensive crisis may occur. It is important to recognize and prevent such catastrophes, for which certain guidelines would be helpful.
• The more potent the drug, the higher the risk of
toxicity.
• When it is essential to use a combination of highly
protein-bound drugs, adjustment of dosage is required for proper and safe
control.
• Any drug that is lipid-soluble at physiological pH
should be considered a candidate for its enzyme-inducing capability, and the
dosage should be appropriately adjusted.
• Authentic manuals on drug interactions must be
readily available for consultation.
• Maintain a detailed drug history and medical record
of the patient.
• Avoid irrational polypharmacy.
Combinations of drugs are employed in therapy to enhance
effects and prevent adverse reactions. Beneficial drug interactions have a
special place in the treatment of diseases, like essential hypertension,
tuberculosis, and cancer. Here mention must also be made about fixed-dose
combination products available in the market. Some fixed-dose combinations are
rational, e.g. combination of a local anesthetics with adrenaline to provide more
effective and prolonged anesthesia.
Pharmacists with knowledge of pharmacological actions,
drug interaction, ADRs of medications, and the pathophysiology of disease can make drug
therapy safer.
Pharmacists should involve in the following steps of
identification and monitoring of adverse drug reactions.
• Patient History: The pharmacist should check
whether the patient has a history of an allergic disorder. It is anticipated
that 10% to 25% of the patient population is hypersensitive to one drug or
another. The pharmacist may reduce the likelihood of these reactions by asking
the patient whether or not he has ever experienced an allergic reaction to a
drug. If the answer is “yes”, the pharmacist should then inquire as to the type
of ADR and the drug that is supposed to induce it.
Adverse drug reactions caused due over-dosage of
medications can be detected by scrutinizing the physician’s prescription about
the recommended dosage. Sedatives and
hypnotics are of major concern in patient overdoses. The pharmacist should
attempt to maintain the number of such products dispensed below toxic
levels.
• Drug Profile Records: The patient profile or
complete family health record can assist in controlling and preventing adverse
drug reactions. The pharmacist is capable of knowing all of the medications
used by these patients by maintaining a health record.
• Literature Review: Pharmacists and physicians
should check properly published literature and package insert information of
drugs and give the proper attention regarding the suspected adverse drug effect
of drugs.
• Drug Level Studies: If the adverse drug reaction
is dose-dependent then the pharmacist should check the drug levels in
biological fluids. Computer, software’s can be used for checking drug levels as
well as drug-drug, drug-diet, and drug-disease interactions.
• Therapeutic Decision Making: The advice of
the pharmacist is very valuable regarding the immediate discontinuation of
therapy in the case of ADRs. Pharmacists should check the risk/benefit ratio of
the continued administration of drugs against the availability of other drugs.