1. In allergy sufferers, histamine causes runny nose, red eyes, and other symptoms. Here is its structural formula.
a. Give the chemical formula for this compound: C5H9N3
b. Circle the amine functional groups in histamine:
c. Which part (or parts) of the molecule make the compound water-soluble: Amine group and -NH group form hydrogen bonds makes the molecule water soluble.
2. Antihistamines are widely used drugs for treating symptoms of allergies caused by reactions to histamine compounds. This class of drug competes with histamine, occupying receptor sites on cells normally occupied by histamine. Here is the structure for a particular antihistamine.
a. Give the chemical formula for this compound: C16H21N3
b. What similarities do you see between this structure and that of histamine (shown in the previous question 1) that would allow the antihistamine to compete with histamine?
Both molecules have amine functional group. However, the amine functional group on antihistamine is less reactive as it is more hindered.
3. Consider this statement. “Drugs can be broadly classed into two groups: those that produce a physiological response and those that inhibit the growth of substances that cause infections.” Into which class does each of these drugs fall?
Physiological response: morphine, estrogen, amphetamine
Inhibit infections: aspirin, antibiotic, penicillin
4. Herbal or alternative medicines are not regulated in the same way as prescription or OTC medicines. In particular, the issues of concern are identification and quantification of the active ingredient, quality control in manufacture, and side effects when the herbal remedy is used in conjunction with another alternative or prescription medicine.
a. What do you think is the evidence from herbal supplement manufacturer that address these issues?
Evidence can be gathered from the new and unknown side effects from the herbal medicines. These side effects may not be identified because clinical trial regulations may not be as strict prior to the release of the herbal medicine.
b. Do you know anything about Singapore’s legislation on the topic?
Singapore requires clinical trials to be done for all medicines, however, the stringency of each class of medicine may differ. Therefore, legislation for herbal medicine may not be as strict as that of a brand-name drug. Singapore do require manufacturers to ensure that all herbal medicine do not contain any substance controlled under the Poison Act; the heavy metal content do not exceed the stated amount; the labels and packaging materials of the herbal medicine do not stipulate any of the 19 diseases/conditions specified in the Schedule of the Medicines Act.