Drug synergy

Question 1

What four stages of the HIV life cycle are targeted by anti-HIV drugs?

Answer 1

Binding (CCR5 antagonists)
Fusion (Bind GP41)
Integration (integrase inhibitors)
Maturation (protease inhibitors)

Question 2

What is Enfuvirtide?

Answer 2

GP41 antagonist

GP41 is important for mediating fusion between virus and host cell

Question 3

What is Zidvudine?

Answer 3

(AZT) Nucleoside reverse transcriptase inhibitor

Question 4

What is Nevirapine?

Answer 4

Non-nucleoside reverse transcriptase inhibitor.

Question 5

What combinations of drugs are used in HAART?

Answer 5

Triple therapy:
2xNRTI + NNRTI
2xNRTI + PI
NRTI + NNRTI + PI

Question 6

What is Tenofovir?

Answer 6

NRTI

Question 7

What is Sofosbuvir?

Answer 7

NS5B polymerase inhibitor.

NS5B is an enzyme required by HCV to copy its RNA

Question 8

How does the synergy between Flucocytosine and amphotericin work?

Answer 8

Amphotericin targets ergosterol and forms pores in fungal membrane, which allows more flucytosine to enter the cell and inhibit DNA synthesis.

Question 9

What is Co-trimoxazole and how does it work?

Answer 9

Sulfonamide + Trimethoprim
Sulfonamide inhibits an enzyme involved in Folate synthesis (PABA-Folate)
Trimethoprim inhibits conversion of folate to tetrahydrofolate.

Question 10

How is Ondansetron used as a synergistic treatment in chemotherapy?

Answer 10

Treats nausea and vomiting caused by chemotherapy - increases the patient’s tolerance to chemotherapy - potential to increase dose

Question 11

What are 6 classes of immunosuppressants?

Answer 11

1. Glucocorticoids
2. Cytotoxic drugs
3. Calcineurin inhibitors (induces transcription factors responsible for cytokine transcription)
4. Targeting cytokine receptors or cytokines
5. T-lymphocyte depletion (antibodies)
6. Co-stimulation block (antibodies)

Question 12

What is an example of calcineurin?

Answer 12

Cyclosporin

Question 13

What are three drugs used as combination therapy for cancer chemotherapy?

Answer 13

Cisplatin/bleomycin cause breakages in DNA/damage to neoplastic cells
Etoposide: inhibits Topoisomerase, which is responsible for repairing DNA allowing cell to survive.
Ondansetron: treats nausea

Question 14

What are two stages in immunosuppressant regimen?

Answer 14

Induction (Often T-cell depletion, monoclonal Ab, before transplant)
Mainainance (maintained immunosuppression after transplant)

Question 15

What is interesting about the drug Targin?

Answer 15

It is both an opioid antagonist and agonist.
Antagonist treats the GIT side-effects (constipation) caused by the agonist activity.
Naloxone: antagonist. stays in the GIT.
Oxycodone: agonist