Drug interactions & unique SE

Question 1

Cyp450 inducers

Answer 1

decrease metabolism of other drugs leading to requiring modified doses

E.g. Phyntoin,phenobarbital,st.John’s, carbamazapine, Rifampin

Question 2

cyp450 inhibitors

Answer 2

Ketoconazaole, Quinidine

Question 3

Most common disease interaction seen with Chlorphenarmin/phenylephrine

Answer 3

BPH

Mechanism:
Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors.

Question 4

Grey baby syndrome caused by:

Answer 4

Chloramphenicol

Question 5

Gray man syndrome caused by:

Answer 5

Amiodarone

Question 6

Red Man syndrome:

Answer 6

Vancomycin

Question 7

Purple toe syndrome:

Answer 7

Warfarin

Question 8

visual impairment is associated with which anti-TB drugs?

Answer 8

Ethambutol

Question 9

Burning sensation in the feet is associated with which anti-TB?

Answer 9

Isoniazid

Question 10

metallic taste is associated with:

Answer 10

Metformin & metronidazole

Question 11

loss of taste is associated with:

Answer 11

Captopril

Question 12

The action of digoxin can be reduced with:

Answer 12

Antacids and hyperhtyrodism, hyperkalemia

Question 13

Process require CYP450:

Answer 13

Oxidation

Question 14

Adsorption

Answer 14

irreversible chemical property

Question 15

Which of the following decrease gastric emptying rate:

Answer 15

hypothyrodism, Atropine

Question 16

Sulfahydryl-group related complications such as: rash, taste abnormalities, nephrotic syndrome is associated with:

Answer 16

Captopril (This is why max dose is limited to 100-150mg/day)

Question 17

Inducers of P-gp

Answer 17

inducers of P-gp drug efflux may decrease serum concentrations of substrates of P-gp.

Phenytoin

Carbamazepine

Rifampin (rifampicin)

Question 18

Inhibitors of P-gp

Answer 18

Inhibitors of the P-gp drug efflux pump (also known as P-gp multidrug resistance transporter) : increase serum concentrations of drugs that are substrates of P-gp

Amiodarone, Carvedilol

Azithromycin, Clarithromycin

Ketoconazole (systemic), Itraconazole

Verapamil, Quinidine, Ranolazine

Question 19

Mechanism of drug interaction between Nitrates and PDE-5 inhibitors:

Answer 19

both Nitrate inhibit the enzyme Guanylyl Cyclase which is responsible for transforming GTP to cGMP thus causing vasodilation smooth muscles and PDE5 inhibitors inhibit the degradation of cGMP by PED-5 enzyme which lead to accumulation cGMP leading to profound relaxation of smooth muscles, dangerous hypotension and decreased perfusion to critical organs.

Question 20

If a patient who has taken a phosphodiesterase-5 inhibitor for erectile dysfunction develops chest pain, delay nitrate therapy for…………… hours after taking avanafil, …………….. hours after taking sildenafil or vardenafil, and ……………..hours after taking tadalafil.

Answer 20

If a patient who has taken a phosphodiesterase-5 inhibitor for erectile dysfunction develops chest pain, delay nitrate therapy for ≥12 hours after taking avanafil, ≥24 hours after taking sildenafil or vardenafil, and ≥48 hours after taking tadalafil.

Question 21

Luminous phenomena due to the fact that in the Retina of the eye there are If channels, bradycardia, AV block, Afib are SE associated with:

Answer 21

Ivabradine (PROCORALAN): Atnti-anginal

Question 22

Managing peripheral edema caused by CCB particularly with Dihydro

Answer 22

The peripheral edema is related to redistribution of fluid from the vascular space into the interstitium. In theory, increased calcium channel blocker-mediated vasodilation leads to increased pressure and subsequent permeability in the capillary circulation The risk of edema is more common with dihydropyridines than with non-dihydropyridines and appears to be dose dependent.

Calcium channel blocker-mediated edema may prompt clinicians to prescribe diuretics, especially loop diuretics, which increase polypharmacy and may cause harm in patients without hypervolemia. However, since calcium channel blocker-mediated edema is not the result of increased plasma volume, it tends not to improve with diuretic therapy. Conversely, addition of an inhibitor of the renin-angiotensin system (RAS), either an angiotensin-converting enzyme (ACE) inhibitor, an angiotensin receptor blocker (ARB), or a direct renin inhibitor can significantly reduce the incidence and severity of edema caused by calcium channel blockers. This effect is probably related to ACE inhibitor- or ARB-mediated venodilation that helps to reduce transcapillary pressure.

As such, edema caused by dihydropyridine calcium channel blockers can be treated by any combination of the following: reduction in dose, switch to a non-dihydropyridine agent, and/or addition of a RAS-blocking agent.

Question 23

SE of nitrates:

Answer 23

Toxicity led by production of methmeglobinemia which can be reverted by the antidote: Methylene blue

Headache “Throbbing”: advice patient to take analgesics during first week.

Tachycardia (Marked) due to baroreceptors compensatory reflexes. Decrease dose gradually especially with continuous IV infusions.

Postural hypotension (due to venodialator effects of nitrates) avoid abrupt postural changes such as standing abruptly.

Question 24

Amyl nitrite: inhaled nitrates

Significant SE of nitrates:

Answer 24

Methemoglobinemia: a blood disorder in which the hemoglobin can carry oxygen, but is not able to release it effectively to body tissues.can be acquired or inherited.

Antidote: Methylene blue is a specific treatment for nitrite toxicity. It causes a rapid conversion of methemoglobin to hemoglobin.

Question 25

Ergot alkaloids and derivatives have been associated with

Answer 25

fibrotic valve thickening (eg, aortic, mitral, tricuspid); usually associated with long-term, chronic use

Question 26

use of Cellcept should be avoided in patients with the rare hereditary deficiency of ………………………. (such as ……………………….. syndrome).

Answer 26

hypoxanthine-guanine phosphoribosyltransferase (such as Lesch-Nyhan or Kelley-Seegmiller syndrome).

Question 27

Cellcpt: A dose of …………… EC-MPS is therapeutically equivalent to ………….. of MMF

Answer 27

A dose of 720 mg EC-MPS is therapeutically equivalent to 1000 mg of MMF

Question 28

CONTRAINDICATIONS of Cellcept:

Answer 28

Pregnancy — risk of 1st trimester pregnancy loss and congenital malformations, including cleft lip and palate, anomalies of the distal limbs, heart, esophagus, and kidneys.

Lactation

Active infection

Question 29

Mycophenolate (Cellcept) is

Answer 29

known as mycophenolic acid [MPA]

powerful inhibitor of lymphocyte proliferation

Question 30

Which of following is least sedative action?

Answer 30

Temazepam

Question 31

Isopretrenol is

Answer 31

Non-selective Beta1/Beta2 Agonist. (dose-dependent)

used for the treatment of bradycardia (slow heart rate), heart block, and rarely for asthma. It is a non-selective β adrenoceptor agonist that is the isopropylamine analog of epinephrine (adrenaline).

Question 32

Cholystyramin resin act by :

Answer 32

Anion exchange

Question 33

Calcipotriol is indicated for

Answer 33

Diarrhea

Question 34

The equation that determine the acid & base degree is

Answer 34

BRONESTED EQUATION

Question 35

Cinchonism is associated with which anti-arrhythmic agent?

Answer 35

Quinidine (Class 1a) consists of tinnitus, blurred vision, dizziness, nausea and vomiting. Quinidine is also used to treat malaria.

Question 36

purple Glove syndrome and Gingival hyperplasia are associated with:

Answer 36

pheyntoin

Question 37

Naranjo scale:

Answer 37

A causality assessment method for assessing all forms of drug induced adverse event
A scale

Question 38

A score of >9 on Naranjo scale means:

Answer 38

Definite: The reaction (1) followed a reasonable temporal sequence after a drug or in which a toxic drug level had been established in body fluids or tissues, (2) followed a recognized response to the suspected drug, and (3) was confirmed by improvement on withdrawing the drug and reappeared on reexposure.

Question 39

A score of <0 on Naranjo scale means:

Answer 39

doubtful: The reaction was likely related to factors other than a drug.

Question 40

Which drug not given to children because it make teeth discoloration :

Answer 40

Doxycycline

Question 41

Linezolid (Zyvox) food interaction include:

Answer 41

Concurrent ingestion of foods rich in tyramine, dopamine, tyrosine, phenylalanine, tryptophan, or caffeine may cause sudden and severe high blood pressure (hypertensive crisis or serotonin syndrome). Beverages containing tyramine (eg, hearty red wine and beer) may increase toxic effects.

Question 42

cyclophosphamide toxicity?

Answer 42

hemorrhagic cystitis