NEET MDS Lessons
Pharmacology
Heroin (diacetyl morphine)
Heroin is synthetically derived from the natural opioid alkaloid morphine
Largely owing to its very rapid onset of action and very short half-life, heroin is a popular drug of abuse
It is most effective when used intravenously
Heroin is rapidly deacetylated to 6-monoacetyl morphine and morphine, both of which are active at the mu opioid receptor
More lipid soluble than morphine and about 2½ times more potent. It enters the CNS more readily.
Clotrimazole: Clotrimazole is a potent, specific inhibitor of p450 enzymes.
It is used in some antifungal medications, and in the treatment of yeast infections.
Diphenoxylate (present in Lomotil)
- A meperidine congener
- Not absorbed very well at recommended doses.
- Very useful in the treatment of diarrhea.
Class IV Calcium Channel Blockers
• Block the movement of calcium into conductile and contractile myocardial cells
• Treatment: treatment of supraventricular tachycardia
– Diltiazem
– Verapamil
Adverse Effects
• Adverse effects associated with vasodilation of blood vessels throughout the body.
• CNS – dizziness, weakness, fatigue, depression and headache,
• GI upset, nausea, and vomiting.
• Hypotension CHF, shock arrhythmias, and edema
Ibuprofen
used to relieve the symptoms of arthritis, primary dysmenorrhoea, fever; and as an analgesic, especially where there is an inflammatory component.
Indications
rheumatoid arthritis, osteoarthritis, juvenile rheumatoid arthritis, primary dysmenorrhoea
fever, relief of acute and/or chronic pain states in which there is an inflammatory component
MOA
inhibition of cyclooxygenase (COX); thus inhibiting prostaglandin synthesis.
Meperidine (Demerol)
Meperidine is a phenylpiperidine and has a number of congeners. It is mostly effective in the CNS and bowel
- Produces analgesia, sedation, euphoria and respiratory depression.
- Less potent than morphine, 80-100 mg meperidine equals 10 mg morphine.
- Shorter duration of action than morphine (2-4 hrs).
- Meperidine has greater excitatory activity than does morphine and toxicity may lead to convulsions.
- Meperidine appears to have some atropine-like activity.
- Does not constrict the pupils to the same extent as morphine.
- Does not cause as much constipation as morphine.
- Spasmogenic effect on GI and biliary tract smooth muscle is less pronounced than that produced by morphine.
- Not an effective antitussive agent.
- In contrast to morphine, meperidine increases the force of oxytocin-induced contractions of the uterus.
- Often the drug of choice during delivery due to its lack of inhibitory effect on uterine contractions and its relatively short duration of action.
- It has serotonergic activity when combined with monoamine oxidase inhibitors, which can produce serotonin toxicity (clonus, hyperreflexia, hyperthermia, and agitation)
Adverse reactions to Meperidine
• Generally resemble a combination of opiate and atropine-like effects.
- respiratory depression, - tremors, - delirium and possible convulsions, - dry mouth
• The presentation of mixed symptoms (stupor and convulsions) is quite common in addicts taking large doses of meperidine.
SGLT-2 Inhibitors
canagliflozin
empagliflozin
Mechanism
glucose is reabsorbed in the proximal tubule of the nephron by the sodium-glucose cotransporter 2 (SGLT2)
SGLT2-inhibitors lower serum glucose by increasing urinary glucose excretion
the mechanism of action is independent of insulin secretion or action
Clinical use
type II DM