*Beta blockers are drugs which act against the beta adrenergic receptors. There are three kinds of adrenergic receptors namely beta1, beta2 and beta3.
*First generation beta blockers (non-selective beta blockers) :
- Propranolol
- Nadolol
- Timolol
- Penbutalol
- Pindolol
- Oxprenolol
- Alprenolol
*Second generatin beta blockers ( Beta1 selective beta blockers = Cardioselective beta blockers ):
- Acebutalol
- Celiprolol
- Bisoprolol
- Metaprolol
- Nebivolol (most cardioselective beta blocker)
- Atenolol
- Esmolol
- Betaxolol
*Third generation beta blockers ( These are beta blockers which have additional vasodilator property ):
- Labetalol and Carvedilol ( act as vasodilators by antagonising alpha1 receptors on blood vessels)
- Tilosolol ( act as vasodilator by opening up potassium channels)
- Nebivolol and Nipradilol ( generate Nitric oxide )
- Bevantolol, Betaxolol, Carvedilol ( inhibit calcium channels )
- Bopindolol, Carteolol, Celiprolol ( agonists of beta2 receptors )
* Beta blockers with Membrane stabilising activity (local anaesthetic activity) :
- Propranolol (most effective)
- Labetalol
- Acebutolol
- Metaprolol
- Pindolol
* Beta blockers with intrinsic sympathomimetic activity :
- Oxprenolol
- Alprenolol
- Pindolol
- Celiprolol
* Beta blockers which are lipid insoluble ( so they are excreted by kidney and hence contraindicated in renal failure - LONG ACTING AGENTS ) :
- Nadolol
- Sotalol
- Acebutalol
- Atenolol
- Betaxolol
- Bisoprolol
- Celiprolol
* Longest acting beta blocker is Nadolol
* Shortest acting beta blocker is esmolol.
Tuesday, December 28, 2010
Sunday, May 9, 2010
65 - Drugs causing CYP3A inhibition
1. HIV antivirals : Indinavir, nelfinavir, ritonavir, Saquinavir
2. Clarithromycin
3. Itraconazole and Ketaconazole
4. Nefazodone
5. Telithromycin
6. Aprepitant
7. Erythromycin
8. Grapefruit juice
9. verapamil, diltiazem
10. Cimetidine
11. Amiodarone
12. Chloramphenicol
13. Ciprofloxacin
14. Delaviridine
15. Diethyl-dithiocarbamate
16. fluvoxamine
17. gestodene
18. Imatinib
19. Mibefradil
20. Mifepristone
21. Norfloxacin
22. Norfluoxetine
23. Starfruit
24. Voriconazole
2. Clarithromycin
3. Itraconazole and Ketaconazole
4. Nefazodone
5. Telithromycin
6. Aprepitant
7. Erythromycin
8. Grapefruit juice
9. verapamil, diltiazem
10. Cimetidine
11. Amiodarone
12. Chloramphenicol
13. Ciprofloxacin
14. Delaviridine
15. Diethyl-dithiocarbamate
16. fluvoxamine
17. gestodene
18. Imatinib
19. Mibefradil
20. Mifepristone
21. Norfloxacin
22. Norfluoxetine
23. Starfruit
24. Voriconazole
Friday, March 19, 2010
64 - AIPGME 2005 Pharmacology Mcqs with answers
1q: A highly ionized drug
a. Is excreted mainly by the kidney
b. Can cross the placental barrier easily
c. Is well absorbed from the intestine
d. Accumulates in the cellular lipids
2q: All of the following hormones have cell surface receptors except
a. Adrenaline
b. GH
c. Insulin
d. Thyroxine
3q: Which one of the following is true of adrenal suppression due to steroid therapy?
a. It is not associated with atrophy of adrenal glands
b. It does not occur in patients receiving inhaled steroids
c. It should be expected in anyone receiving greater than 5mg of prednisolone daily
d. Following cessation, the stress response normalizes after 8 weeks
4q: With which of the following theophylline has an antagonistic interaction?
a. Histamine receptors
b. Bradykinin receptors
c. Adenosine receptors
d. Imidazoline receptors
5q: Which one of the following drugs increases gastrointestinal motility?
a. Glycopyrrolate
b. Atropine
c. Neostigmine
d. Fentanyl
6q: Which one of the following drugs has been shown to offer protection from gastric aspiration syndrome in a patient with symptoms of flux?
a. Ondansetron
b. Metaclopramide
c. Sodium citrate
d. Atropine
7q: The following drugss have significant drug interactions with digoxin except :
a. Cholestyramine
b. Thiazide diuretics
c. Quinine
d. Amlodipine
8q: One of the following is not true about nesiritide
a. It is a brain natriuretic peptide analogue
b. It is used in acutely decompensated heart failure
c. It has significant oral absorption
d. It has a short half life
9q: Dry mouth during antidepressant therapy is caused by blockade of
a. Muscarinic acetylcholine receptors
b. Serotonergic receptors
c. Dopaminergic receptors
d. GABA receptors
10q: The major difference between typical and atypical antipsychotics is that
a. The latter cause minimal or no increase in prolactin
b. The former cause tardive dyskinesia
c. The former are available as parenteral preparations
d. The latter cause substantial sedation
11q: Antipsychotic drug induced parkinsonism is treated by
a. Anticholinergics
b. Levodopa
c. Selegilline
d. Amantadine
12q: Oculogyric crisis is known to be produced by all of the following drugs except
a. Trifluoperazine
b. Atropine
c. Perchlorperazine
d. Perphenazine
13q: Inverse agonist of benzodiazepine receptor is
a. Phenobarbitone
b. Flumazenil
c. Beta-carboline
d. Gabapentin
14q: All of the following are hallucinogens except
a. LSD
b. Phencyclidine
c. Mescaline
d. Methylphenidate
15q: All of the following are topically used sulphonamides except
a. Sulphacetamide
b. Sulphadiazine
c. Silver sulphadiazine
d. Mafenide
16q: One of the following is not pencillinase susceptible
a. Amoxicillin
b. Pencillin G
c. Piperacillin
d. Cloxacillin
17q: The group of antibiotics which possess additional anti-inflammatory and immunomodulatory activities is
a. Tetracyclines
b. Polypeptide antibiotics
c. Fluoroquinolones
d. Macrolides
18q: Which one of the following is best associated with Lumefantrine?
a. Antimycobacterial
b. Antifungal
c. Antimalarial
d. Antiamoebic
19q: Which one of the following is used in therapy of Toxoplasmosis?
a. Artensunate
b. Thiacetazone
c. Ciprofloxacin
d. Pyrimethamine
20q: Nevirapine is a
a. Protease inhibitor
b. Nucleoside reverse transcriptase inhibitor
c. NNRTI
d. Fusion inhibitor
21q: Which one of the following drugs is "Topoisomerase I" inhibitor?
a. Doxorubicin
b. Irinotecan
c. Etoposide
d. Vincristine
22q: Etanercept acts by one of the following mechanisms
a. By blocking Tumor necrosis factor
b. By blocking bradykinin synthesis
c. By inhibiting COX-2
d. By blocking lipoxygenase
a. Is excreted mainly by the kidney
b. Can cross the placental barrier easily
c. Is well absorbed from the intestine
d. Accumulates in the cellular lipids
2q: All of the following hormones have cell surface receptors except
a. Adrenaline
b. GH
c. Insulin
d. Thyroxine
3q: Which one of the following is true of adrenal suppression due to steroid therapy?
a. It is not associated with atrophy of adrenal glands
b. It does not occur in patients receiving inhaled steroids
c. It should be expected in anyone receiving greater than 5mg of prednisolone daily
d. Following cessation, the stress response normalizes after 8 weeks
4q: With which of the following theophylline has an antagonistic interaction?
a. Histamine receptors
b. Bradykinin receptors
c. Adenosine receptors
d. Imidazoline receptors
5q: Which one of the following drugs increases gastrointestinal motility?
a. Glycopyrrolate
b. Atropine
c. Neostigmine
d. Fentanyl
6q: Which one of the following drugs has been shown to offer protection from gastric aspiration syndrome in a patient with symptoms of flux?
a. Ondansetron
b. Metaclopramide
c. Sodium citrate
d. Atropine
7q: The following drugss have significant drug interactions with digoxin except :
a. Cholestyramine
b. Thiazide diuretics
c. Quinine
d. Amlodipine
8q: One of the following is not true about nesiritide
a. It is a brain natriuretic peptide analogue
b. It is used in acutely decompensated heart failure
c. It has significant oral absorption
d. It has a short half life
9q: Dry mouth during antidepressant therapy is caused by blockade of
a. Muscarinic acetylcholine receptors
b. Serotonergic receptors
c. Dopaminergic receptors
d. GABA receptors
10q: The major difference between typical and atypical antipsychotics is that
a. The latter cause minimal or no increase in prolactin
b. The former cause tardive dyskinesia
c. The former are available as parenteral preparations
d. The latter cause substantial sedation
11q: Antipsychotic drug induced parkinsonism is treated by
a. Anticholinergics
b. Levodopa
c. Selegilline
d. Amantadine
12q: Oculogyric crisis is known to be produced by all of the following drugs except
a. Trifluoperazine
b. Atropine
c. Perchlorperazine
d. Perphenazine
13q: Inverse agonist of benzodiazepine receptor is
a. Phenobarbitone
b. Flumazenil
c. Beta-carboline
d. Gabapentin
14q: All of the following are hallucinogens except
a. LSD
b. Phencyclidine
c. Mescaline
d. Methylphenidate
15q: All of the following are topically used sulphonamides except
a. Sulphacetamide
b. Sulphadiazine
c. Silver sulphadiazine
d. Mafenide
16q: One of the following is not pencillinase susceptible
a. Amoxicillin
b. Pencillin G
c. Piperacillin
d. Cloxacillin
17q: The group of antibiotics which possess additional anti-inflammatory and immunomodulatory activities is
a. Tetracyclines
b. Polypeptide antibiotics
c. Fluoroquinolones
d. Macrolides
18q: Which one of the following is best associated with Lumefantrine?
a. Antimycobacterial
b. Antifungal
c. Antimalarial
d. Antiamoebic
19q: Which one of the following is used in therapy of Toxoplasmosis?
a. Artensunate
b. Thiacetazone
c. Ciprofloxacin
d. Pyrimethamine
20q: Nevirapine is a
a. Protease inhibitor
b. Nucleoside reverse transcriptase inhibitor
c. NNRTI
d. Fusion inhibitor
21q: Which one of the following drugs is "Topoisomerase I" inhibitor?
a. Doxorubicin
b. Irinotecan
c. Etoposide
d. Vincristine
22q: Etanercept acts by one of the following mechanisms
a. By blocking Tumor necrosis factor
b. By blocking bradykinin synthesis
c. By inhibiting COX-2
d. By blocking lipoxygenase
Thursday, March 4, 2010
63 - Amiodarone
*Amiodarone is an iodine containing long acting antiarrythmic drug which belongs to class III.
*Mechanism of action : It prolongs actional potential duration and effective refractory period is also prolonged. Conduction is slowed. When the drug is given through oral route, it has minimal effect on cardiac contractility and BP. Amiodarone is categorized as a class III antiarrhythmic agent, and prolongs phase 3 of the cardiac action potential. It has numerous other effects however, including actions that are similar to those of antiarrhythmic classes Ia, II, and IV. Amiodarone shows beta blocker-like and potassium channel blocker-like actions on the SA and AV nodes, increases the refractory period via sodium- and potassium-channel effects, and slows intra-cardiac conduction of the cardiac action potential, via sodium-channel effects.
Amiodarone resembles thyroid hormone, and its binding to the nuclear thyroid receptor might contribute to some of its pharmacologic and toxic action
*Uses : It is used in resistant cases of VT and recurrent VF. It is used in resistant cases of AF when other drugs have failed.
*ADVERSE EFFECTS :
- It interferes with thyroid function : Both hypothyroidism and hyperthyroidism may be seen. It inhibits peripheral conversion of T4 to T3.
- Cardiac depressant action : This is seen on IV injection but not on oral dose. On IV administration fall in BP and myocardial depression occurs.
- Peripheral neuropathy
- Pulmonary alveolitis and fibrosis
- Photosensitization
- Corneal microdeposits.
*Mechanism of action : It prolongs actional potential duration and effective refractory period is also prolonged. Conduction is slowed. When the drug is given through oral route, it has minimal effect on cardiac contractility and BP. Amiodarone is categorized as a class III antiarrhythmic agent, and prolongs phase 3 of the cardiac action potential. It has numerous other effects however, including actions that are similar to those of antiarrhythmic classes Ia, II, and IV. Amiodarone shows beta blocker-like and potassium channel blocker-like actions on the SA and AV nodes, increases the refractory period via sodium- and potassium-channel effects, and slows intra-cardiac conduction of the cardiac action potential, via sodium-channel effects.
Amiodarone resembles thyroid hormone, and its binding to the nuclear thyroid receptor might contribute to some of its pharmacologic and toxic action
*Uses : It is used in resistant cases of VT and recurrent VF. It is used in resistant cases of AF when other drugs have failed.
*ADVERSE EFFECTS :
- It interferes with thyroid function : Both hypothyroidism and hyperthyroidism may be seen. It inhibits peripheral conversion of T4 to T3.
- Cardiac depressant action : This is seen on IV injection but not on oral dose. On IV administration fall in BP and myocardial depression occurs.
- Peripheral neuropathy
- Pulmonary alveolitis and fibrosis
- Photosensitization
- Corneal microdeposits.
Sunday, February 21, 2010
62 - Adverse effects, Precautions and Contraindications of Chloroquine
Toxicity and Side Effects:
Taken in proper doses, chloroquine is an extraordinarily safe drug; however, its safety margin is narrow, and a single dose of 30 mg/kg may be fatal (Taylor and White, 2004). Acute chloroquine toxicity is encountered most frequently when therapeutic or high doses are administered too rapidly by parenteral routes. Toxic manifestations relate primarily to the cardiovascular system and the CNS. Cardiovascular effects include hypotension, vasodilation, suppressed myocardial function, cardiac arrhythmias, and eventual cardiac arrest. Confusion, convulsions, and coma indicate CNS dysfunction. Chloroquine doses of more than 5 g given parenterally usually are fatal. Prompt treatment with mechanical ventilation, epinephrine, and diazepam may be lifesaving.
Doses of chloroquine used for oral therapy of the acute malarial attack may cause GI upset, headache, visual disturbances, and urticaria. Pruritus also occurs, most commonly among dark-skinned persons. Prolonged medication with suppressive doses occasionally causes side effects such as headache, blurring of vision, diplopia, confusion, convulsions, lichenoid skin eruptions, bleaching of hair, widening of the QRS interval, and T-wave abnormalities. These complications usually disappear soon after the drug is withheld. Rare instances of hemolysis and blood dyscrasias have been reported. Chloroquine may cause discoloration of nail beds and mucous membranes. Chloroquine can interfere with the immunogenicity of certain vaccines (Horowitz and Carbonaro, 1992; Pappaioanou et al., 1986).
Irreversible retinopathy and ototoxicity can result from high daily doses (>250 mg) of chloroquine or hydroxychloroquine that lead to cumulative total doses of more than 1 g of base per kilogram body weight, such as those used for treatment of diseases other than malaria. Retinopathy presumably is related to drug accumulation in melanin-rich tissues and can be avoided if the daily dose is 250 mg or less (see Rennie, 1993). Prolonged therapy with high doses of 4-aminoquinoline also can cause toxic myopathy, cardiopathy, and peripheral neuropathy; these reactions improve if the drug is withdrawn promptly (Estes et al., 1987). Rarely, neuropsychiatric disturbances, including suicide, may be related to overdose.
Precautions and Contraindications :
This topic has been reviewed by Taylor and White (2004). Chloroquine is not recommended for treating individuals with epilepsy or myasthenia gravis. The drug should be used cautiously if at all in the presence of hepatic disease or severe gastrointestinal, neurological, or blood disorders. The dose must be adjusted in renal failure. In rare cases, chloroquine can cause hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency (see Primaquine below). Concomitant use of gold or phenylbutazone (no longer available in the United States) with chloroquine should be avoided because of the tendency of all three agents to produce dermatitis. Chloroquine should not be prescribed for patients with psoriasis or other exfoliative skin conditions because it causes severe reactions. It should not be used for malaria in patients with porphyria cutanea tarda but is used in smaller doses for treatment of the underlying disease . Chloroquine is an inhibitor of CYP2D6 and interacts with a variety of different agents. It should not be given with mefloquine because of increased risk of seizures. Most important, this antimalarial opposes the action of anticonvulsants and increases the risk of ventricular arrhythmias from coadministration with amiodarone or halofantrine. By increasing plasma levels of digoxin and cyclosporine, chloroquine also can increase the risk of toxicity from these agents. For patients receiving long-term, high-dose therapy, ophthalmological and neurological evaluations are recommended every 3 to 6 months.
Taken in proper doses, chloroquine is an extraordinarily safe drug; however, its safety margin is narrow, and a single dose of 30 mg/kg may be fatal (Taylor and White, 2004). Acute chloroquine toxicity is encountered most frequently when therapeutic or high doses are administered too rapidly by parenteral routes. Toxic manifestations relate primarily to the cardiovascular system and the CNS. Cardiovascular effects include hypotension, vasodilation, suppressed myocardial function, cardiac arrhythmias, and eventual cardiac arrest. Confusion, convulsions, and coma indicate CNS dysfunction. Chloroquine doses of more than 5 g given parenterally usually are fatal. Prompt treatment with mechanical ventilation, epinephrine, and diazepam may be lifesaving.
Doses of chloroquine used for oral therapy of the acute malarial attack may cause GI upset, headache, visual disturbances, and urticaria. Pruritus also occurs, most commonly among dark-skinned persons. Prolonged medication with suppressive doses occasionally causes side effects such as headache, blurring of vision, diplopia, confusion, convulsions, lichenoid skin eruptions, bleaching of hair, widening of the QRS interval, and T-wave abnormalities. These complications usually disappear soon after the drug is withheld. Rare instances of hemolysis and blood dyscrasias have been reported. Chloroquine may cause discoloration of nail beds and mucous membranes. Chloroquine can interfere with the immunogenicity of certain vaccines (Horowitz and Carbonaro, 1992; Pappaioanou et al., 1986).
Irreversible retinopathy and ototoxicity can result from high daily doses (>250 mg) of chloroquine or hydroxychloroquine that lead to cumulative total doses of more than 1 g of base per kilogram body weight, such as those used for treatment of diseases other than malaria. Retinopathy presumably is related to drug accumulation in melanin-rich tissues and can be avoided if the daily dose is 250 mg or less (see Rennie, 1993). Prolonged therapy with high doses of 4-aminoquinoline also can cause toxic myopathy, cardiopathy, and peripheral neuropathy; these reactions improve if the drug is withdrawn promptly (Estes et al., 1987). Rarely, neuropsychiatric disturbances, including suicide, may be related to overdose.
Precautions and Contraindications :
This topic has been reviewed by Taylor and White (2004). Chloroquine is not recommended for treating individuals with epilepsy or myasthenia gravis. The drug should be used cautiously if at all in the presence of hepatic disease or severe gastrointestinal, neurological, or blood disorders. The dose must be adjusted in renal failure. In rare cases, chloroquine can cause hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency (see Primaquine below). Concomitant use of gold or phenylbutazone (no longer available in the United States) with chloroquine should be avoided because of the tendency of all three agents to produce dermatitis. Chloroquine should not be prescribed for patients with psoriasis or other exfoliative skin conditions because it causes severe reactions. It should not be used for malaria in patients with porphyria cutanea tarda but is used in smaller doses for treatment of the underlying disease . Chloroquine is an inhibitor of CYP2D6 and interacts with a variety of different agents. It should not be given with mefloquine because of increased risk of seizures. Most important, this antimalarial opposes the action of anticonvulsants and increases the risk of ventricular arrhythmias from coadministration with amiodarone or halofantrine. By increasing plasma levels of digoxin and cyclosporine, chloroquine also can increase the risk of toxicity from these agents. For patients receiving long-term, high-dose therapy, ophthalmological and neurological evaluations are recommended every 3 to 6 months.
61 - Drugs potentially harmful in Porphyria
1. BARBITURATES : The effect of barbiturates on ALA synthetase can cause dangerous disease exacerbations in persons with intermittent porphyria.Because barbiturates enhance porphyrin synthesis, they are absolutely contraindicated in patients with acute intermittent porphyria or porphyria variegata.
2. ETHCHLORVYNOL: Ethchlorvynol may enhance the hepatic metabolism of other drugs such as oral anticoagulants, and it is contraindicated in patients with intermittent porphyria.
3. CHLOROQUINE : It should not be used for malaria in patients with porphyria cutanea tarda but is used in smaller doses for treatment of the underlying disease.
2. ETHCHLORVYNOL: Ethchlorvynol may enhance the hepatic metabolism of other drugs such as oral anticoagulants, and it is contraindicated in patients with intermittent porphyria.
3. CHLOROQUINE : It should not be used for malaria in patients with porphyria cutanea tarda but is used in smaller doses for treatment of the underlying disease.
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