Question

Q2.The response of a patient to a medicine depends upon the patient’s genetic make-up and upon environmental factors such as a patients’s microbiome. (a) Give two key reasons, with explanations, why genetic variation can affect a patient’s response to a drug.

(b) Explain why environmental factors such as a patients’s microbiome can affect a patient’s response to a drug.

Q3. Write short notes of the following topics. Your answers should be illustrated with appropriate examples. (i) The importance of considering hERG in drug discovery. (ii) The discovery of lead compounds from venom and toxins. (iii) Privilaged structures in drug design. (iv) “Mix and Split” combinatorial chemistry.

Answer 1

2.

a.Genetic variation can affect a patient's response to a drug because:

• Genetic variation gives rise to different drug metabolizing genes that metabolise a particuar drug in different ways in different people.
• It is ue to genetic variation among individuals that body responds to the drug in a different manner.We can say that genetic variation decides  what drug does to our body and what the drug does to our body. For example, it is due to  genetic variation that  people process or metabolize the same drugs in different ways i.e slowly or fast.

b.Environmental factors such as a patients’s microbiome can affect a patient’s response to a drug because these  bacteria produce enzymes and release other molecules that can affect or influence how the drugs are activated or metabolised.Example : Parkinson's drug levodopa (L-dopa)has been reported to show different efficacy among different individuals.

3.

i ) The importance of considering hERG in drug discovery. This is done to avoid cardiac toxicity as it is found that reduction in the  function of hERG leads to  potential action prolongation as well as  increase in the  the risk for ventricular arrhythmia.So, preclinical hERG testing becomes very  essential in the drug discovery.

ii) The discovery of lead compounds from venom and toxins :The discovery of lead compounds from venom and toxins prove to be very promising. Combination of pharmaceutical properties can be used  in making use of lead compunds in venom toxins as this proves to be valuable pharmacological tool and as leads in drug development process.These lead compounds can be tailored to achieve desirable biocompatibility and biodegradability with simultaneously selective and potent therapeutic effects.

iii) Privilaged structures in drug design :They play an important rolein designing bioactive molecules.The use of privileged structures is a sort of viable strategy in the process of  of new drug discovery during the lead optimization stages of the drug discovery.

iv ) Mix and Split combinatorial chemistry: This technique was introduce by Furka and co-workers in 1988 for synthesizing large peptide libraries.In this technique, the starting material first undergoes splitting in ‘n’ portions, and then reacted with ‘n’ building block to be  recombined in one flask. For the second step, again this procedure is repeated. This process  is particularly used for solid phase synthesis.