ANTIVIRAL (SN)

❕write MOA of acyclovir?*
(require 3 phosphorylation steps)
1. inhibits viral DNA synthesis
2. competitive inhibitor with deoxy GTP for viral DNA polymerase
3. bind to template (irreversible) > chain termination

❕write MOA and A/E of zidovudine?
▫️converted to triphosphate by thymidine kinase
▫️incorporate into chain of viral DNA > chain termination
1. myelosuppresion
2. headache insomnia anxiety
3. hyperpigmentation of nail - myopathy

-------------------------------------------
ANTIFUNGAL (SN)

❕write MOA of amphotericin B?*
1. binds to ergosterol and alters permeability by forming pores
2. allows leakage of ions > cell death

❕list A/E of amphotericin B?**
1. fever chills
2. renal impairment (due to decrease GFR)
3. hypotension (shock with hypokalemia)
4. anemia (due to reduced erythropoietin production)

*pharmacokinetics of fluconazole* mcq مهم

*imidazoles & triazoles* مهم الفروقات بيناتهن

❕list A/E of griseofulvin?
1. headache vomiting diarrhea
2. photosensitivity peripheral neuritis
3. hepatotoxicity
4. coumarin anticoagulant activity altered

ANTICANCER (SN)

❕write MOA of alkylating agents (cyclophosphamide)?*
1. work by covalent binding of alkyl group to guanine
2. cross link DNA in intra strand & inter strand manner > interrupt DNA replication

❕write MOA of cytotoxic antibiotics (doxorubicin)?*
1. intercalate with DNA base pairs causing breakage of DNA
2. inhibit enzyme topoisomerase II > damage - apoptosis

❕write MOA of trastuzumab?*
1. binds to HER2 > inhibit signaling + activation
2. activate ADCC

❕list A/E of anticancer drugs?**
1. bome marrow suppression
2. damages lining of the mouth and intestines > bacteria enter blood
3. nausea vomiting
4. temporary hair loss
5. rashes - sterility
6. peripheral neuropathy - ototoxicity
7. tumor lysis syndrome > arrhythmia - seizures - acute kidney failure - death

EXPLAIN PART

CNS

❗explain why BZDs cause antergrade amnesia?
▫️b/c events are not transformed from short term memory to long term memory

❗explain why long acting BZDs are not used in sleep disorders?
▫️to prevent day time sedation

❗explain why barbiturates cause more hangover?
▫️b/c marked reduction in REM - stage 3, 4 NREM

❗explain why barbiturates CI in acute intermittent porphyria?
▫️b/c increase heme synthesis

❗explain why methadone and buprenorphine are used in detoxification of addicts?
▫️b/c it has lower dependance and abuse potential - long duration of action

❗explain why pethedine is preferred during labor?
▫️b/c it has less respiratory depression in neonates and does not delay labor

❗explain why pethedine should not be used in chronic pain?
▫️b/c less potent rapid and shorter duration

❗explain why fentanyl is preferred in anaesthesia?
▫️b/c strong analgesic and sedation in preanesthesia
induce and maintain anesthesia

❗explain why remifentanyl induces less ventilatory depression than morphine?
▫️b/c ultra short acting metabolized by blood and tissue esterase

❗explain why naltrexone is used in management of chronic opioid toxicity while naloxone is used in acute?
▫️b/c naltrexone: decrease craving for opioids after weeks
naloxone: works within 2 min only

❗explain why morphine CI with BPH?
▫️b/c cause urine retention

❗explain why morphine CI in bilary colic?
▫️b/c cause contraction of the gall and constriction of sphinctor

❗explain why NO used in combination with oxygen?
▫️b/c it moves quickly and retard oxygen uptake during recovery causing diffusional hypoxia

❗explain why local anesthetic less effective when they are injected into infected tissues?
▫️b/c low PH favors charged form with less neutral base available for diffusion across membrane

❗explain why epinephrine is added to LA?
▫️b/c it's VC > increase duration and reduce systemic absorption and toxicity

❗epenpherine should not be administrated in areas as fingers and toes?
▫️b/c it may cause ischemia - necrosis

❗explain why allergy to one type of ester means allergy to all?
▫️because PABA is the allergic metabolite produced by all esters

❗explain why monotherapy is preferred in anti epileptic drugs?
▫️b/c they are either enzyme inducers or enzyme inhibitors

❗explain why use of phenytoin is limited?
▫️due to: 1. irregular bioavailability
2. saturation kinetics unpredictable serum lvl.
3. drug interaction if combined

❗explain why barbiturates and BZDs are not 1st choice agents in ttt of epilepsy?
▫️due to sedation and tolerance

❗explain how optimization of L-dopa therapy could be achieved by it's combination with peripheral dopa carboxylase inhibitors?
▫️b/c does not cross BBB > increase lvl. of dopamine and decrease peripheral side effects

❗Levodopa cause fluctuation in response (on - off phenomena)?
1. decrease sensitivity of D receptors
2. fluctuation in L-dopa plasma (short half life)
* corrected by giving drug holidays (3-21 days)

❗explain why pyridoxine should be avoided in parkinsonism pt. using L-dopa?
▫️b/c vit. B6 enhance activity of dopa decarboxylase and increase peripheral metabolism of L-dopa

❗explain why low protein diet is advised in parkinson?
▫️b/c protein to interfere with how levodopa is absorbed on the body

❗explain why non ergot DA agonist (pramipexil) are preferable to ergots in ttt of parkinson?
▫️b/c ergot alkaloids cause VC - urine retraction and stim. central D receptor

❗explain why lithium not used with loop diuretics?
▫️b/c it competes with Na for tubular reabsorption
Na depletion > increase lithium reabsorption > increase serum lithium > toxicity

❗TCAs and antidepressants should be used cautiosly in bipolar disorder?
▫️b/c antidepressants may cause a switch to manic behaviour

ENDOCRINE (explain why)

❗️explain why long acting insulin not used?
▫️due to delayed onset (no control PP hyperglycemia) and long duration (hypoglycemia)

❗️explain why oral hypoglycemics not used with type I DM?
▫️b/c depends on presence of functioning Beta cells

❗️explain why insulin release decreased when hypokalemia?
▫️b/c it needs K for depolarization

❗️explain why sulfonylurea increase insulin release?
▫️b/c close ATP sensitive K ch.

❗️explain why in severe renal - liver ds. stress - pregnancy insulin and not oral antidiabetics must be used?
▫️b/c oral hypoglycemics are not approved by the FDA (teratogenic)
▫️b/c is removed from circulation by liver and kidney

❗️explain why metformin is CI in renal - liver failure and in severe hypoxia?
▫️b/c 1. it acc. increase risk of lactic acidosis
2. hepatic metabolism of lactic acid is impaired
3. lactic acidosis reduces drug elimination or reduces tissue oxygenation

❗️explain why miglitol cause inflammatory bowel ds.?
▫️b/c acc. of undigested carb. which may cause gas and distention

-------------------------------------------------
❗️explain why methimazole is prefered to propylthiouracil for ttt hyperthyroidism?
▫️b/c it has lower risk of serious liver injury and can be administered once daily

❗️explain why propylthiouracil is preferred to methimazole during pregnancy?
▫️b/c more strongly protein bound crosses placenta less readily

❗️explain why iodide should not be used alone and for long period?
▫️because the gland will escape from the iodide block in 2-8 weeks

-------------------------------------------------
❗️explain why natural sex hormones are not used clinically?
▫️b/c it undergoes 1st pass metabolism

❗️explain why rifampicin decreases the efficact of oral contraceptives?
▫️b/c it is a hepatic inducer increase metabolism of contraceptives

❗️explain why contraceptives fail when use antibiotics?
▫️b/c antibiotics kill bacteria and estrogen is hydrolyzed in intestine by bacteria so decrease it's effect

❗️explain why progestins are added to oestrogen in contraceptive pills?
▫️b/c together decrease endometrium glycogen as to discourage implantation and make cervical mucus
or Unopposed Estrogen predisposes to Endometrial Carcinoma

-------------------------------------------------
❗️explain why steroids are used in stress - cerebral edema - hypercalcemia?
▫️b/c prevents acute adrenal crisis

▫️decrease swelling - hotness - pain

▫️decrease Ca in bl. - bone by decrease activation of vit. D in liver

❗️why not give NSAIDs with glucocorticoids?
▫️to avoid peltic ulcer

❗️mouth wash after each steroid inhalation?
▫️to prevent candidiasis

-------------------------------------------------
❗️explain why bisphosphonates (alendronate) is taken while sitting & with full glass of water?
▫️b/c cause gastric and esophageal irritation

ASTHMA (explain why)

❗explain why SABA agonists are 1st choice bronchodilators?
▫️rapidly effective safe inexpensive

❗explain why inhaled LABA have to be combined with corticosteroids and not to be given alone as controllers?
▫️b/c their anti inf. effect is insignificant and bronchodilator effect mask progressive asthma severity (+mortality)

❗explain the use of adrenaline in bronchial asthma and why it's replaced by selective beta 2?
▫️b/c short duration
▫️non selective: a) beta 1 effect > tachy
b) alpha effect > increase BP

❗explain advantage of tiotropium over ipratopium?
▫️not ass. with tolerance

❗explain why theophylline is considered 2nd line drug in asthma?
▫️b/c 1. require drug monitoring
2. narrow safety margin
3. drug interactions

❗explain why leukotriene antagonists are drug of choice for control of aspirin induced asthma?
▫️due to LTs production from arachidonic acid through LOX pathway following blockade of COX by aspirin

❗explain why LT antagonist are preffered in children?
▫️b/c it's oral easier than inhalation and well tolerated

❗explain why status asthmaticus is refractory to the usual line of ttt?
▫️due to down regulation of beta R - mucous plug -acidosis

GIT (explain why)

❗proton pump inhibitors have short half life acid inhibition last up to 24 hours?
▫️b/c of irreversible inactivation of the proton pump at least 18 hrs for synthesis of new H/K ATPase

❗explain why Al hydroxide and Mg are most commonly used antacid?
▫️no CO2 release or systemic alkalosis
▫️used combined to neutrilize effects of each other

❗explain why antacids should be cautiously used in elderly & renal impairment?
▫️chelate phosphates > induce osteomalacia encephalopathy Alzheimer cns depression

❗explain why misoprostol is rarely used?
▫️b/c it needs frequent stim. (4 times daily)

❗antacids should not be given within 2 hrs of doses?
▫️b/c effect absorption of other drugs by binding or increasing gastric PH

ANTIFUNGAL (explain why)

❗amphotericin B is selective in fungicidal effect?
▫️b/c it diff. b/w lipid composition of fungi and mammalian

❗drug interaction is less common with fluconazole?
▫️b/c has the least effect of all azole on hepatic enzyme interaction

❗nystatin is limited to topical ttt only?
▫️b/c narrow spectrum and no absorption from GIT

ان شاء الله كملت تنزيل جزئية الشورت نوت و الإكسبلاين اللي بعد الجزئي~
إكسبلاين CVS نزلتها مسبقا في القناة مثبت مع اهم نقاطها~

يفضل الantibiotic في نقاط مهمة نزلتها زميلتنا في قناتها بارك الله فيها 👇

أهم نقاط ال antibiotic ⁉️⁉️💡💡🧠

تركيزات الجامعة والمهم في ال Antibiotics ❤️.

⁉️⁉️ Warfarin 🆚 Heparin

بعض الإضافات اللي مش قاعدات في بي دي اف الشورت نوت:

❕uses of morphine?
1. anaelgesia
2. diarrhea
3. cough
4. acute pul. edema with lt. vent. failure
6. anaesthesia

❕uses of antidepressants?
1. major depression disorder
2. anxiety disorders
3. pain disorders
4. urinary incontinence
5. eating disorders
6. smoking cessation
7. prophylaxis of migraine

❕TTT of acute decompensated HF

❕drugs induced blood disorders

❕MOA of nitroprusside?
NO donor > increase C GMP > induce VD by inhibit Ca influx

❕indications of parenteral iron therapy?

و في الPDF جزئية GA سؤال الثاني بدال كلمة adjuncts غيروه stages 😅

شكرا لكل من دز و نبه عليهن 🤍

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