Quiz 5: Adverse Drug Effects and Drug Interactions
The further questions which can be asked to the patient about drug allergies are whether there is a previous exposure to the drug codeine, as reexposure to the drug sensitizes the patient and hyperresponse the body defenses. Whether they are using any other drugs as drug allergy is nonspecific and it is difficult sometimes to ascertain the allergy symptom to any given drug. Whether they are having allergy to any food or whether there are any insect stings or bite by any insects etc., as the symptoms of drug allergy are similar to those of allergy caused by other substances like certain foods or environmental triggers like insect stings, animal dander or dust mites.
The pharmacokinetic drug interactions include the changes in the absorption, distribution, metabolism or excretion of medications. The presence of food and drug-drug binding reduced the absorption of the drug. The alteration of pH, increased peristalsis and slowed gastric emptying varies the absorption of the drug. The displacement of drug from blood plasma protein binding site increases the distribution of the drug. Certain drugs may induce the hepatic enzyme activity of other drugs, leading to the diminished effect of the drug and some drugs may inhibit the hepatic enzyme activity of other drugs, leading to the increased effect of the drug. Increased excretion causes decreased effect of drug and decreased excretion causes increased effect of drug. Based on the above effects of food or drugs on the pharmacokinetic parameters, the absorption, distribution, metabolism or excretion of other drugs may be influenced in a very significant way. So, the first-pass effect plays an important role on the pharmacotherapy as the amount of drug available to show the response depends on the first-pass effect on the drug.
The ways by which the adverse drug events can be minimized or prevent in this patient is by obtaining thorough medical history and by thoroughly assessing the patient and all diagnostic data. Thorough medical history reveal the drug allergies or conditions that contraindicated the use of particular drugs and it also helps to identify the different drugs which could negatively interact with the prescribed medication. Thoroughly assessing the patient and all diagnostic data reveal the underlying problems related to renal and hepatic impairment and the way it will affect the handling of drug by the body. The average drug doses are adjusted based on the assessment of patient carefully, to prevent adverse effects.