ADR management
Predisposing Factors:
Polypharmacy:
Patients on multiple drug therapy are more prone to develop an ADR either due
to alteration of drug effect through an interaction mechanism or by synergistic
effect.
The amount of risk associated with multiple drug therapy increases with an
increase in the number of drugs administered.
Multiple and intercurrent diseases:
Patients with multiple diseases are at increased risk of developing an ADR due to
multiple drug use for their diseases.
Similarly, patients with impaired hepatic or renal status are also at high risk of
developing an ADR to drugs which are eliminated by these organs.
For example, a patient with decreased renal function who is treated with
aminoglycosides is at increased risk of developing nephrotoxicity unless
appropriate dose adjustments are made.
Age:
Elderly and pediatric patients are more vulnerable to ADRs. Elderly patients are
more susceptible to ADRs due to the physiological changes (pharmacokinetic
and pharmacodynamic) which accompany ageing, and also because they often
take many drugs for chronic and multiple diseases.
Drug characteristics:
Some drugs are highly toxic in nature and patients who are treated with these
agents are at an increased risk of ADRs. For example, nausea and vomiting is a
common ADR seen in patients treated with cytotoxic anti-cancer drugs.
Also, patients who are treated with drugs which have a narrow therapeutic
range such as digoxin and gentamicin are more susceptible, as a slight increase
in the serum concentration of these drugs may result in toxicity.
Gender:
Women are reported to be more susceptible to ADRs than men, for a number of
reasons: physiological,pharmacokinetic, pharmacodynamic and hormonal.
Chloramphenicol-induced aplastic anemia and phenylbutazone-induced
agranulocytosis are twice and thrice as common in women as in men,
respectively.
Race and genetic factors:
It is evident that ADRs are more common in genetically predisposed individuals.
