Consequences Of Drug Interaction In The Use Of AEDs (Essay Sample)

CONSEQUENCES OF DRUG INTERACTION IN THE USE OF AEDs
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Medical professionals usually prescribe antiepileptic drugs(AEDs) for monotherapy and long term adjunctive therapy to treat epilepsy and other symptoms (Johannesen & Landmark, 2018). The composition of AEDs includes drugs that are highly prone to drug interactions (Johannesen & Landmark, 2018). The purpose of this essay is to examine clinically important interactions involving AEDs and their consequences. We can categorize the interactions as pharmacokinetic interactions with older AEDs and pharmacokinetic with newer AEDs.
Firstly, older AEDs cause pharmacokinetic interactions that lead to inhibition or induction. Enzyme induction is a process that yields new enzymes and it involves protein synthesis (Johannesen & Landmark, 2018). The course of induction needs many days to reach its final stages. The effects of induction include forfeiture of seizure regulation, diminished serum concentrations, pharmacological effects in the absence of active metabolites and an increased metabolism (Johannesen & Landmark, 2018).
On the other hand, enzyme inhibition is a consequence of the competition for the active site of an enzyme by various drugs and its result is the diminished metabolism of a drug. An increase in the circulating concentration of the affected drug occurs resulting in pharmacological potentiation, which occurs at a rate commensurate with the half life of the drug (Czuczwar et al., 2009). Accordingly, it transpires rapidly if the drug has a brief half life and at a slower rate in case the drug has a longer half-life. Moreover, upon the elimination of the inhibitor, the drug concentrations reduce while placing the patient at risk of seizures (Johannessen Landmark & Johannessen, 2008).
Secondly, pharmacokinetic interactions with latest AEDs involve the enzyme inducers topiramate and oxcarbazepine (Czuczwar et al., 2009). The interactions also involve enzyme inhibitors stiripentol, rufinamide and felbamate. These drugs also affect other drug groups, for instance, oral contraceptives, older AEDs, and lamotrigine (Johannessen Landmark & Johannessen, 2008). We can divide the interactions into three levels according to the clinical effects of changes in the serum concentrations.
The first level describes interactions with grave clinical consequences and medical experts should take great care to avoid the combinations. An instance is the combination of the AED Carbamazepine with oral contraceptives. The interaction between the above drugs is harmful and it causes the diminishing of serum concentrations, impairing of the functions of the contraceptive and the triggering of estrogen metabolism.
Level 2 interactions describe those interactions that require caution and dosage adjustments since they are hard to avoid. An example of a level 2 interaction is the combination of the AED valproic acid with lamotrigine (Johannesen & Landmark, 2018). The interaction instigates the blocking of lamotrigine metabolism, increases the concentration of serum thus causing the emergence of skin rashes and neurotoxic symptoms. Therefore, monitoring and dosage modifications will mitigate the effects of level 2 interactions. Level 3 interactions are those interactions that have a minor influence on serum concentrations and consequently, their effects are not serious enough to require dosage adjustments (Tatum, 2010).
In conclusion, older AEDs may instigate interactions that lead to enzyme inhibition or induction. Newer AEDs are also prone to interactions, due to their application in adjunc...