As an anthelmintic mebendazole has the following advantages except: A. It is active against most intestinal helminths B. It is very well tolerated C. Single dose cures roundworm and hookworm infestation D. It does not require predrug fasting or postdrug purging

As an anthelmintic mebendazole has the following
advantages except:
A. It is active against most intestinal helminths
B. It is very well tolerated
C. Single dose cures roundworm and hookworm infestation
D. It does not require predrug fasting or postdrug purging
by

1 Answer

Answer :

C. Single dose cures roundworm and hookworm infestatio
by

Related questions

Thiabendazole is rarely used now because: A. It frequently produces incapacitating side effects B. It produces lower cure rates in intestinal helminthiasis than mebendazole or albendazole C. It needs pretreatment fasting and post treatment purgative D. It is not active against roundworm and hookworm

Description : Thiabendazole is rarely used now because: A. It frequently produces incapacitating side effects B. It produces lower cure rates in intestinal helminthiasis than mebendazole or albendazole C. It ... fasting and post treatment purgative D. It is not active against roundworm and hookworm

Last Answer : A. It frequently produces incapacitating side effects

The following is true of levamisole except: A. A single dose cures over 90% cases of round worm infestation B. It is more effective against Necator americanus than against Ancylostoma duodenale C. It has immunomodulating action D. Its prolonged use causes severe reactions

Description : The following is true of levamisole except: A. A single dose cures over 90% cases of round worm infestation B. It is more effective against Necator americanus than against Ancylostoma duodenale C. It has immunomodulating action D. Its prolonged use causes severe reactions

Last Answer : B. It is more effective against Necator americanus than against Ancylostoma duodenale

A saline purgative is recommended following: A. Niclosamide for tapeworm infestation B. Mebendazole for roundworm infestation C. Pyrantel pamoate for hookworm infestation D. Albendazole for whipworm infestation (Trichuriasis

Description : A saline purgative is recommended following: A. Niclosamide for tapeworm infestation B. Mebendazole for roundworm infestation C. Pyrantel pamoate for hookworm infestation D. Albendazole for whipworm infestation (Trichuriasis

Last Answer : A. Niclosamide for tapeworm infestation

For the treatment of Hymenolepis nana infestation, praziquantel has the following advantage(s) over niclosamide: A. It is better tolerated B. It requires single dose treatment against 5 days treatment with niclosamide C. A purgative is required after niclosamide but not after praziquantel D. All of the abov

Description : For the treatment of Hymenolepis nana infestation, praziquantel has the following advantage(s) over niclosamide: A. It is better tolerated B. It requires single dose treatment against 5 days treatment with ... C. A purgative is required after niclosamide but not after praziquantel D. All of the abov

Last Answer : B. It requires single dose treatment against 5 days treatment with niclosamide

A child has been brought with intestinal obstruction due to clumping of roundworms. Select the anthelmintic which administered by intragastric tube can relax the ascarids and relieve the obstruction: A. Levamisole B. Mebendazole C. Pyrantel pamoate D. Piperazine

Description : A child has been brought with intestinal obstruction due to clumping of roundworms. Select the anthelmintic which administered by intragastric tube can relax the ascarids and relieve the obstruction: A. Levamisole B. Mebendazole C. Pyrantel pamoate D. Piperazine

Last Answer : D. Piperazine

Piperazine antagonises the anthelmintic action of the following drug: A. Pyrantel pamoate B. Mebendazole C. Albendazole D. Niclosamide

Description : Piperazine antagonises the anthelmintic action of the following drug: A. Pyrantel pamoate B. Mebendazole C. Albendazole D. Niclosamide

Last Answer : A. Pyrantel pamoate

he following anthelmintic acts as a cholinergic agonist in the nematodes and causes spastic paralysis of the worms: A. Piperazine B. Pyrantel pamoate C. Mebendazole D. Thiabendazole

Description : he following anthelmintic acts as a cholinergic agonist in the nematodes and causes spastic paralysis of the worms: A. Piperazine B. Pyrantel pamoate C. Mebendazole D. Thiabendazole

Last Answer : B. Pyrantel pamoate

The following helminthic disease can be treated by albendazole but not by mebendazole: A. Hookworm infestation B. Threadworm infestation C. Trichuriasis D. Neurocysticercosis

Description : The following helminthic disease can be treated by albendazole but not by mebendazole: A. Hookworm infestation B. Threadworm infestation C. Trichuriasis D. Neurocysticercosis

Last Answer : D. Neurocysticercosis

Albendazole is less effective than mebendazole in the following helminthic infestation: A. Hydatid disease B. Trichuriasis C. Strongyloidosis D. Ascariasis

Description : Albendazole is less effective than mebendazole in the following helminthic infestation: A. Hydatid disease B. Trichuriasis C. Strongyloidosis D. Ascariasis

Last Answer : B. Trichuriasis

In addition to amoebiasis, metronidazole is used for: A. Roundworm infestation B. Hookworm infestation C. Kala-azar D. Giardiasis

Description : In addition to amoebiasis, metronidazole is used for: A. Roundworm infestation B. Hookworm infestation C. Kala-azar D. Giardiasis

Last Answer : D. Giardiasis

Which of the following is a second generation cephalosporin that is highly resistant to gram negative β-lactamases, and cures penicillinase positive as well as negative gonococcal infection by a single intramuscular dose: A. Cephalexin B. Cefuroxime C. Cefoperazone D. Ceftazidime

Description : Which of the following is a second generation cephalosporin that is highly resistant to gram negative β-lactamases, and cures penicillinase positive as well as negative gonococcal infection by a single intramuscular dose: A. Cephalexin B. Cefuroxime C. Cefoperazone D. Ceftazidime

Last Answer : B. Cefuroxime

Angiotensin converting enzyme inhibitors afford maximum protection against progression of heart failure when used: A. At the higher therapeutic dose range over long term B. At the maximum tolerated dose only till haemodynamic compensation is restored C. At low doses over long term D. At low doses along with diuretics/digoxi

Description : Angiotensin converting enzyme inhibitors afford maximum protection against progression of heart failure when used: A. At the higher therapeutic dose range over long term B. At the maximum tolerated dose only till ... restored C. At low doses over long term D. At low doses along with diuretics/digoxi

Last Answer : A. At the higher therapeutic dose range over long term

The distinctive feature of secnidazole is: A. It is not absorbed after oral ingestion B. It is recommended for single dose treatment of intestinal amoebiasis C. It is effective in intestinal but not in hepatic amoebiasis D. It is effective in both trichomonas as well as monilial vaginitis

Description : The distinctive feature of secnidazole is: A. It is not absorbed after oral ingestion B. It is recommended for single dose treatment of intestinal amoebiasis C. It is effective in intestinal but not in hepatic amoebiasis D. It is effective in both trichomonas as well as monilial vaginitis

Last Answer : B. It is recommended for single dose treatment of intestinal amoebiasis

A drug which is generally administered in standard doses without the need for dose individualization is: A. Insulin B. Mebendazole C. Prednisolone D. Digoxin

Description : A drug which is generally administered in standard doses without the need for dose individualization is: A. Insulin B. Mebendazole C. Prednisolone D. Digoxin

Last Answer : B. Mebendazole

The following is true of vancomycin except: A. It is a bactericidal antibiotic active primarily against gram positive bacteria B. It acts by inhibiting bacterial protein synthesis C. It is an alternative to penicillin for enterococcal endocarditis D. It can cause deafness as a dose related toxicity

Description : The following is true of vancomycin except: A. It is a bactericidal antibiotic active primarily against gram positive bacteria B. It acts by inhibiting bacterial protein synthesis C. It is an alternative to penicillin for enterococcal endocarditis D. It can cause deafness as a dose related toxicity

Last Answer : B. It acts by inhibiting bacterial protein synthesis

The following is true of clarithromycin except: A. It produces less gastric irritation and pain than erythromycin B. It is the most active macrolide antibiotic against Helicobacter pylori C. It does not interact with terfenadine or cisapride to cause cardiac arrhythmias D. It exhibits dose dependent elimination kinetics

Description : The following is true of clarithromycin except: A. It produces less gastric irritation and pain than erythromycin B. It is the most active macrolide antibiotic against Helicobacter pylori ... terfenadine or cisapride to cause cardiac arrhythmias D. It exhibits dose dependent elimination kinetics

Last Answer : C. It does not interact with terfenadine or cisapride to cause cardiac arrhythmias

The limitations of quinidine in the treatment of cardiac arrhythmias include the following except: A. It has narrow spectrum antiarrhythmic activity B. It is not tolerated by many patients C. It can precipitate myocardial decompensation D. It can cause marked hypotension

Description : The limitations of quinidine in the treatment of cardiac arrhythmias include the following except: A. It has narrow spectrum antiarrhythmic activity B. It is not tolerated by many patients C. It can precipitate myocardial decompensation D. It can cause marked hypotension

Last Answer : A. It has narrow spectrum antiarrhythmic activity

The following is true of linezolid except: A. It inhibits bacterial protein synthesis at an early step B. It is active against vancomycin resistant enterococci C. It is the drug of choice for enterococcal endocarditis D. It can be administered orally as well as by i.v. infusion

Description : The following is true of linezolid except: A. It inhibits bacterial protein synthesis at an early step B. It is active against vancomycin resistant enterococci C. It is the drug of choice for enterococcal endocarditis D. It can be administered orally as well as by i.v. infusion

Last Answer : C. It is the drug of choice for enterococcal endocarditis

The distinctive feature of nimesulide is: A. It does not inhibit prostaglandin synthesis B. It does not cause gastric irritation C. It is usually well tolerated by aspirin intolerant asthma patients D. It is not bound to plasma proteins

Description : The distinctive feature of nimesulide is: A. It does not inhibit prostaglandin synthesis B. It does not cause gastric irritation C. It is usually well tolerated by aspirin intolerant asthma patients D. It is not bound to plasma proteins

Last Answer : C. It is usually well tolerated by aspirin intolerant asthma patients

The following does not apply to cancer chemotherapy: A. Each treatment with a cytotoxic drug kills a constant number of malignant cells B. Drugs are generally used at maximum tolerated doses C. The same regimen which is palliative for a large solid tumour may be curative after surgical removal of the tumour D. Combination regimens using several drugs in succession are superior to single drug used continuously

Description : The following does not apply to cancer chemotherapy: A. Each treatment with a cytotoxic drug kills a constant number of malignant cells B. Drugs are generally used at maximum tolerated ... D. Combination regimens using several drugs in succession are superior to single drug used continuously

Last Answer : A. Each treatment with a cytotoxic drug kills a constant number of malignant cells

Which anthelmintic drug acts through a specific glutamate gated Cl– ion channel found only in nematodes: A. Ivermectin B. Niclosamide C. Pyrantel pamoate D. Praziquantel

Description : Which anthelmintic drug acts through a specific glutamate gated Cl– ion channel found only in nematodes: A. Ivermectin B. Niclosamide C. Pyrantel pamoate D. Praziquantel

Last Answer : A. Ivermectin

The following anthelmintic has been found to be safe during pregnancy: A. Thiabendazole B. Piperazine C. Albendazole D. Pyrantel pamoate

Description : The following anthelmintic has been found to be safe during pregnancy: A. Thiabendazole B. Piperazine C. Albendazole D. Pyrantel pamoate

Last Answer : B. Piperazine

Anthelmintic action of piperazine is due to: A. Interference with ATP generation in the worm B. Blockade of glucose uptake by the worm C. Hyperpolarization of nematode muscle by GABA agonistic action D. Depolarization of nematode muscle by activating nicotinic receptors

Description : Anthelmintic action of piperazine is due to: A. Interference with ATP generation in the worm B. Blockade of glucose uptake by the worm C. Hyperpolarization of nematode muscle by GABA agonistic action D. Depolarization of nematode muscle by activating nicotinic receptors

Last Answer : C. Hyperpolarization of nematode muscle by GABA agonistic action

The principles of antihypertensive drug usage enunciated in JNC VI and WHO-ISH guidelines include the following except: A. Therapy for grade I and II hypertension should be initiated with a single drug B. Dose of thiazide diuretic should be 12.5-25 mg hydrochlorothiazide or equivalent per day C. All subjects with BP higher than 140/90 mmHg should be put on antihypertensive medication immediately D. If the drug chosen initially fails to lower BP, it should be replaced by a drug/combination from another class

Description : The principles of antihypertensive drug usage enunciated in JNC VI and WHO-ISH guidelines include the following except: A. Therapy for grade I and II hypertension should be initiated with a single drug ... initially fails to lower BP, it should be replaced by a drug/combination from another class

Last Answer : C. All subjects with BP higher than 140/90 mmHg should be put on antihypertensive medication immediately

Clarithromycin and erythromycin have very similar spectrums of antimicrobial activity. The major advantage of clarithromytcin is that it (a) Eradicates mycoplasmal infections in a single dose (b) Is active against strains of streptococci that are resistant to erythromycin (c) Is more active against Mycobacterium avium complex (d) Does not inhibit live drug-metabolizing enzymes (e) Acts on methicillin-resistant strains of staphylococci

Description : Clarithromycin and erythromycin have very similar spectrums of antimicrobial activity. The major advantage of clarithromytcin is that it (a) Eradicates mycoplasmal infections in a single dose (b ... not inhibit live drug-metabolizing enzymes (e) Acts on methicillin-resistant strains of staphylococci

Last Answer : Ans: C

The distinctive feature of terbinafine is: A. It is highly effective in histoplasmosis B. It can be used topically as well as orally for dermatophytosis C. It inhibits Mucor and Aspergillus as well D. Applied intravaginally it cures both candida as well as trichomonas vaginitis

Description : The distinctive feature of terbinafine is: A. It is highly effective in histoplasmosis B. It can be used topically as well as orally for dermatophytosis C. It inhibits Mucor and Aspergillus as well D. Applied intravaginally it cures both candida as well as trichomonas vaginitis

Last Answer : B. It can be used topically as well as orally for dermatophytosis

The most probable mechanism of action of mebendazole is: A. Depolarization of membrane and spastic paralysis of the worm B. Hyperpolarization of membrane and flaccid paralysis of the worm C. Loss of intracellular microtubules and inhibition of glucose uptake in the worm D. Tegument damage and leakage of contents of the worm

Description : The most probable mechanism of action of mebendazole is: A. Depolarization of membrane and spastic paralysis of the worm B. Hyperpolarization of membrane and flaccid paralysis of the worm C. Loss of ... inhibition of glucose uptake in the worm D. Tegument damage and leakage of contents of the worm

Last Answer : C. Loss of intracellular microtubules and inhibition of glucose uptake in the worm

Indicate the drug that is not effective in amoebiasis A. Ornidazole B. Mebendazole C. Satranidazole D. Secnidazole

Description : Indicate the drug that is not effective in amoebiasis A. Ornidazole B. Mebendazole C. Satranidazole D. Secnidazole

Last Answer : B. Mebendazole

Patients treated with the following drug should be cautioned not to consume alcoholic beverages: A. Mebendazole B. Metronidazole C. Methimazole D. Metamizol

Description : Patients treated with the following drug should be cautioned not to consume alcoholic beverages: A. Mebendazole B. Metronidazole C. Methimazole D. Metamizol

Last Answer : B. Metronidazole

Cefotaxime has the following properties except: A. It is highly active against aerobic gram negative bacteria B. It is the most active cephalosporin against Pseudomonas aeruginosa C. It produces an active metabolite D. It has achieved high cure rates in serious hospital acquired infections

Description : Cefotaxime has the following properties except: A. It is highly active against aerobic gram negative bacteria B. It is the most active cephalosporin against Pseudomonas aeruginosa C. It produces an active metabolite D. It has achieved high cure rates in serious hospital acquired infections

Last Answer : B. It is the most active cephalosporin against Pseudomonas aeruginosa

Amoxicillin + Clavulanic acid is active against the following organisms except: A. Methicillin resistant Staph. aureus B. Penicillinase producing Staph. aureus C. Penicillinase producing N.gonorrhoeae D. β-lactamase producing E.coli

Description : Amoxicillin + Clavulanic acid is active against the following organisms except: A. Methicillin resistant Staph. aureus B. Penicillinase producing Staph. aureus C. Penicillinase producing N.gonorrhoeae D. β-lactamase producing E.coli

Last Answer : A. Methicillin resistant Staph. aureus

A drug which is generally administered in standard doses without the need for dose individualization is: A. Insulin B. Mebendazole C. Prednisolone D. Digoxin

Description : A drug which is generally administered in standard doses without the need for dose individualization is: A. Insulin B. Mebendazole C. Prednisolone D. Digoxin

Last Answer : B. Mebendazole

Important microbiological features of ciprofloxacin include the following except: A. Long postantibiotic effect B. Marked suppression of intestinal anaerobes C. MBC values close to MIC values D. Slow development of resistance

Description : Important microbiological features of ciprofloxacin include the following except: A. Long postantibiotic effect B. Marked suppression of intestinal anaerobes C. MBC values close to MIC values D. Slow development of resistance

Last Answer : B. Marked suppression of intestinal anaerobes

The following is true of loperamide except: A. It is absorbed from intestines and exerts centrally mediated antidiarrhoeal action B. It acts on the opioid receptors in the gut C. It increases tone and segmenting activity of the intestines D. It inhibits intestinal secretion by binding to calmodulin in the mucosal cells

Description : The following is true of loperamide except: A. It is absorbed from intestines and exerts centrally mediated antidiarrhoeal action B. It acts on the opioid receptors in the gut C. It increases ... of the intestines D. It inhibits intestinal secretion by binding to calmodulin in the mucosal cells

Last Answer : A. It is absorbed from intestines and exerts centrally mediated antidiarrhoeal action

Metoclopramide has the following actions except: A. Increases lower esophageal sphincter tone B. Increases tone of pyloric sphincter C. Increases gastric peristalsis D. Increases intestinal peristalsis

Description : Metoclopramide has the following actions except: A. Increases lower esophageal sphincter tone B. Increases tone of pyloric sphincter C. Increases gastric peristalsis D. Increases intestinal peristalsis

Last Answer : B. Increases tone of pyloric sphincter

Morphine induced constipation involves the following mechanisms except: A. Increase in tone and decrease in propulsive activity of intestinal muscles B. Antivagal action C. Spasm of gastrointestinal sphincters D. Reduction of gastrointestinal secretions

Description : Morphine induced constipation involves the following mechanisms except: A. Increase in tone and decrease in propulsive activity of intestinal muscles B. Antivagal action C. Spasm of gastrointestinal sphincters D. Reduction of gastrointestinal secretions

Last Answer : B. Antivagal action

5-HT appears to play a role in the following except: A. Regulation of normal BP B. Regulation of intestinal peristalsis C. Haemostasis D. Causation of migraine

Description : 5-HT appears to play a role in the following except: A. Regulation of normal BP B. Regulation of intestinal peristalsis C. Haemostasis D. Causation of migraine

Last Answer : A. Regulation of normal BP

Pentamidine should be used to treat Kala azar only when sodium stibogluconate has failed or is not tolerated because: A. It achieves lower cure rates B. It is more toxic C. It requires a longer course of treatment D. Relapses are more common with it

Description : Pentamidine should be used to treat Kala azar only when sodium stibogluconate has failed or is not tolerated because: A. It achieves lower cure rates B. It is more toxic C. It requires a longer course of treatment D. Relapses are more common with it

Last Answer : B. It is more toxic

Choose the correct statement about severity of side effects to oral iron medication: A. Ferrous salts are better tolerated than ferric salts B. Complex organic salts of iron are better tolerated than inorganic salts C. Liquid preparations of iron are better tolerated than tablets D. Tolerability depends on the quantity of elemental iron in the medication

Description : Choose the correct statement about severity of side effects to oral iron medication: A. Ferrous salts are better tolerated than ferric salts B. Complex organic salts of iron are better ... better tolerated than tablets D. Tolerability depends on the quantity of elemental iron in the medication

Last Answer : D. Tolerability depends on the quantity of elemental iron in the medication

n the treatment of hyperthyroidism, carbimazole has the following advantage over radioactive iodine: A. Cost of treatment is lower B. It is preferable in uncooperative patient C. It is better tolerated by the patients D. Hypothyroidism when induced is reversible

Description : n the treatment of hyperthyroidism, carbimazole has the following advantage over radioactive iodine: A. Cost of treatment is lower B. It is preferable in uncooperative patient C. It is better tolerated by the patients D. Hypothyroidism when induced is reversible

Last Answer : Hypothyroidism when induced is reversible

As an antitubercular drug, isoniazid has the following advantages except: A. It is tuberculocidal B. It acts on both extra and intracellular bacilli C. Tubercle bacilli do not develop resistance against it D. It is cheap

Description : As an antitubercular drug, isoniazid has the following advantages except: A. It is tuberculocidal B. It acts on both extra and intracellular bacilli C. Tubercle bacilli do not develop resistance against it D. It is cheap

Last Answer : C. Tubercle bacilli do not develop resistance against it

Select the drug which is active against a variety of diarrhoea producing organisms like Giardia, Shigella, Salmonella as well as S. typhi and Trichomonas vaginalis, but is not a first line treatment for any of these: A. Metronidazole B. Mepacrine C. Cotrimoxazole D. Furazolidone

Description : Select the drug which is active against a variety of diarrhoea producing organisms like Giardia, Shigella, Salmonella as well as S. typhi and Trichomonas vaginalis, but is not a first line treatment for any of these: A. Metronidazole B. Mepacrine C. Cotrimoxazole D. Furazolidone

Last Answer : D. Furazolidone

Choose the orally active third generation cephalosporin having good activity against gram positive cocci as well: A. Cefdinir B. Ceftazidime C. Cefoperazone D. Ceftizoxime

Description : Choose the orally active third generation cephalosporin having good activity against gram positive cocci as well: A. Cefdinir B. Ceftazidime C. Cefoperazone D. Ceftizoxime

Last Answer : A. Cefdinir

Piperacillin differs from carbenicillin in the following respect(s): A. It is more active against Pseudomonas aeruginosa B. It is active against Klebsiella as well C. It is acid resistant D. Both ‘A’ and ‘B’ are correct

Description : Piperacillin differs from carbenicillin in the following respect(s): A. It is more active against Pseudomonas aeruginosa B. It is active against Klebsiella as well C. It is acid resistant D. Both ‘A’ and ‘B’ are correct

Last Answer : D. Both ‘A’ and ‘B’ are correct

Carbimazole differs from propylthiouracil in that: A. It is dose to dose less potent B. It has a shorter plasma half life C. It does not produce an active metabolite D. It does not inhibit peripheral conversion of thyroxine to triiodothyronine

Description : Carbimazole differs from propylthiouracil in that: A. It is dose to dose less potent B. It has a shorter plasma half life C. It does not produce an active metabolite D. It does not inhibit peripheral conversion of thyroxine to triiodothyronine

Last Answer : D. It does not inhibit peripheral conversion of thyroxine to triiodothyronine

s a general anaesthetic, halothane has the following advantages except: A. Very good analgesic action B. Noninflammable and nonexplosive C. Reasonably rapid induction of anaesthesia D. Pleasant and nonirritating

Description : s a general anaesthetic, halothane has the following advantages except: A. Very good analgesic action B. Noninflammable and nonexplosive C. Reasonably rapid induction of anaesthesia D. Pleasant and nonirritating

Last Answer : A. Very good analgesic action

Praziquantel is preferred over niclosamide for Taenia solium infestation because: A. It achieves higher cure rates B. It produces fewer side effects C. It does not lead to digestion of worm and kills encysted larvae, so that chances of cysticercosis are minimized D. Both ‘A’ and ‘B’ are correct

Description : Praziquantel is preferred over niclosamide for Taenia solium infestation because: A. It achieves higher cure rates B. It produces fewer side effects C. It does not lead to digestion of worm and kills encysted larvae, so that chances of cysticercosis are minimized D. Both ‘A’ and ‘B’ are correct

Last Answer : C. It does not lead to digestion of worm and kills encysted larvae, so that chances of cysticercosis are minimized

Saline osmotic purgatives are used for: A. Treatment of constipation B. Prevention of constipation in patients of piles C. Avoidance of straining at stools in patients of hernia D. Tapeworm infestation: following niclosamide administration

Description : Saline osmotic purgatives are used for: A. Treatment of constipation B. Prevention of constipation in patients of piles C. Avoidance of straining at stools in patients of hernia D. Tapeworm infestation: following niclosamide administration

Last Answer : D. Tapeworm infestation: following niclosamide administration

The following is true of simvastatin except: A. It is more potent than lovastatin B. At the highest recommended dose, it causes greater LDL-cholesterol lowering than lovastatin C. It does not undergo first pass metabolism in liver D. It can raise HDL-cholesterol level when the same is low at base line

Description : The following is true of simvastatin except: A. It is more potent than lovastatin B. At the highest recommended dose, it causes greater LDL-cholesterol lowering than lovastatin C. It does not undergo ... metabolism in liver D. It can raise HDL-cholesterol level when the same is low at base line

Last Answer : C. It does not undergo first pass metabolism in liver