Viva questions in Pharmacology: Introduction and Routes of drug administration
Pharmacology is the branch of medicine concerned with the uses, effects, and modes of action of drugs.
2. What is pharmacodynamics?
What the drug does to the body. This includes physiology and biochemical effects of drugs and their mechanism of action at organ system
3. What is pharmacokinetics?
What the body does to the drug.this refers to the movement of the drug in and alteration of the drug by the body includes absorption, distribution, binding storage, biotransformation and excretion of drug
4. Define Drug
It is the single active chemical entity present in a medicine that is used for diagnosis, prevention and treatment of a disease
5.WHO definition of a Drug
Drug is any substance or product that is used or is intended to be usedto modify or explorephysiological systems orpathological states for thebenefit bof vthe recipient
6.What is toxicology?
It is the study of poisonous effect of drugs and other chemicals with emphasis on detection, prevention and treatment of poisonings. It also includes the study of adverse effects of drugs depending on the dose
7. What is chemotherapy?
It is the treatment of systemic infection or malignancy with specific drugs that have selective toxicity for the infecting organiam or malignant cell with no or minimal effects on the host cells
8.What are the routes of drug administration?
1.Local routes are
- Topical ex: antiseptic gels
- Deeper tissues eg:lignocaine
- Arterial supply eg:anticancer drugs
2. Systemic routes are
- Sublingual or buccal
9. What are the limitations of oral route of administration?
- Action is slower so not suitable for emergencies
- Unpalatable drugs
- May cause nausea and vomiting
- Cannot be used for uncooperative unconscious vomiting patient
- Certain drugs are not absorbed like streptomycin and some others are destroyed by digestive juices like pencilin G , insulin
Factors that affects the choice of route
- Physical and chemical properties of the drug
- Site of desired action
- Rate and extent of absorption of the drug from different routes
- Effect of digestive juices and first pass metabolism on the drug
- Rapidity with which the response is desired
- Accuracy of dosage required
- Condition of the patient
10.What are the disadvantages of parenteral route drug administration?
The preparation has to be sterilized and is costlier, the technique is invasive and painful, assistance of is mostly another person needed.
11.What are the drugs which should not be given by IV route?
Paracetamol, Diclofenac,chloroquine, adrenaline
12.What are the disadvantages of Chloramphenicol?
Previously chloramphenicol is the drug of choice in treatment of typhoid. The main disadvantages are bone marrow depression and aplastic anemia, gray baby syndrome, hypersensitivity reactions, super infection
13.What are the adverse effects of Tetracycline?
- renal toxicity and fanconi syndrome,
- suppression of bone marrow growth
- staining of teeth due to chelates formation
14..What is the most common side effect of ampicillin oral administration?
Diarrhoea is the most common side effect due to incomplete absorption of the drug and the unabsorbed drug irritates the lower intestine
15. What are the common side effects of streptomycin?
Nephrotoxicity, ototoxicity, and contact sensitization are common side effects, 8th nerve is usually effected. Vestibular involvement is more common and cochlear involvement is less common
Some other Points in this topic
- The important aspects of pharmacology are pharmacotherapeutics, clinical pharmacology, chemotherapy, pharmacy and toxicology
- Pharmacy:-I t is the art and science of compounding and dispensing drugs or preparing suitable dosage forms for administration of drugs to man or animals
- A drug generally has three categories of names those are Chemical name, Nonproprietary name, proprietary (brand) name. The term generic name is used in place of nonproprietary name.
- Highly lipid soluble drugs can be applied over the skin for slow and prolonged absorption
- All drugs administered orally is subjected to first pass metabolism in intestinal wall and liver, while half of that absorbed from rectum passes through liver. Drug entering from any systemic route is exposed to first pass metabolism in lungs, but its extent is minor for most drugs.