IC18 STI Flashcards

Question

(1) NRTI: Adverse effects | zidovudine, abacavir

Answer 1

**Abacavir** * N/V/D * Hypersensitivity reaction in patients with HLA-B*5701 *Discontinue if occurs & do not rechallenge Require testing for HLA-B5701 before initiation* * Association with MI ⇒ avoid in high CVD risk patients **zidovudine** * N/V/D * Myopathy * Bone marrow suppression ⇒ causes anemia/ neutropenia (To monitor FBC)

Answer 2

bictegravir raltegravir elvitegravir dolutegravir

Answer 3

Bictegravir & dolutegravir ⇒ good virologic effectiveness High genetic barrier to resistance [B&D > R&E] Generally well tolerated

Answer 4

Bioavailability lowered by concurrent administration of polyvalent cations Bictegravir, dolutegravir & elvitegravir ⇒ CYP 3A4 substrates

Answer 5

weight gain, diarrhoea, nausea & headache Depression & suicidality in those with pre-existing psychiatric conditions

Answer 6

increase SCr Inhibits tubular secretion of creatinine

Answer 7

Pyrexia Elevation of CK ⇒ rhabdomyolysis

Answer 8

efavirenz Rilpivirine

Answer 9

* Long t1/2 ⇒ OD dosing * Less metabolic toxicities than with some PIs Hyperlipidemia, insulin resistance

Answer 10

* Low genetic barrier for resistance * Cross resistance among approved NNRTIs * Skin rash, SJS [R < E] * Potential for CYP450 drug interactions → inducers & inhibitors **Efavirenz**: CYP3A4 substrate, CYP2B6 and 2C19 inducer **Rilpivirine**: CYP3A4 substrate, oral absorption is reduced with increased gastric pH; use with PPIs is contraindicated. * QTc prolongation

Answer 11

**Efavirenz** * Rash * Hyperlipidemia: increased LDL-C & TG * Neuropsychiatric SE: dizziness, depression, insomnia, abnormal dreams, hallucination * Hepatotoxicity **Rilpirivine** CNS: Depression & headache

Answer 12

Liponavir Azatanavir Darunavir Fosamprenavir Ritonavir

Answer 13

High genetic barrier to resistance

Answer 14

* Metabolic complications → dyslipidemia, insulin resistance * GI SE → N/V/D * Liver toxicity (especially with chronic hepatitis B or C) * CYP3A4 inhibitors & substrates: potential for DDI * Morphologic Complications → Fat maldistribution (Lipohypertrophy) * Increased risk of osteopenia/osteoporosis

Answer 15

* Potent CYP3A4, 2D6 inhibitor * PK enhancer → combined with other PI [Lopinavir/ritonavir] to increase the other PI concentration levels **SE**: paresthesia (numbness of extremities) & taste perversion

Answer 16

(+) Good GI tolerability & less lipid effects * Absorption depends on low pH Contraindication with PPIs **SE**: hyperbilirubinemia, prolong QT interval, skin rash

Answer 17

(+) Good GI tolerability & less lipid effects (-) Skin rash & concern for SJS Due to **sulfonamide** component

Answer 18

Enfuvirtide SC injection BD no DDI

Answer 19

* **Injection site reaction**→ erythema/ induration, nodules/ cyst, pruritis, ecchymosis * **Rare hypersensitivity** → fever, chills, decrease BP, rash * Increased bacterial pneumonia

Answer 20

Only for those with strains of HIV **using CCR5 receptor to enter CD4 cells** * Need co-receptor tropism assay before initiation (to check which receptor HIV uses to enter cells) * Must be **CCR5 predominant**

Answer 21

**Potential DDI**: CYP3A4 substrate **ADR**: Abdominal pain, cough, dizziness, musculoskeletal symptoms, pyrexia, rash, upper respiratory tract infections, hepatotoxicity, orthostatic hypotension

Answer 22

Syphilis: Treponema pallidum Gonorrhoea: Neisseria gonorrhoeae Non-gonococcal urethritis Chlamydia

Answer 23

herpes simplex virus (HSV) HIV

Answer 24

* Mainly by sexual contact with infected person * **Direct contact** of broken skin with open sores, blood or genital discharge Must be deep/ big * Receiving contaminated blood Important to start on post-exposure prophylaxis Usually screened to ensure no STI in blood * From infected mother to child During **pregnancy** → ie: syphilis, HIV During **childbirth** → ie: chlamydia, gonorrhoea, HSV **Breastfeeding** → ie: HIV

Answer 25

* Unprotected sexual intercourse * Number of sexual partner Those with **multiple sexual partners**→ more likely to acquire & transmit STI Those with **sexual contact with people who have multiple sexual partners** * MSM * Prostitution (CSW) → covers first 2 points * Illicit drug use → ie sharing of needle by IV drug users

Answer 26

* Abstinence & reduction of number of sexual partners long-term, mutually monogamous relationship with an uninfected partner * Barrier contraceptive methods male latex condoms when used consistently & correctly * Avoid drug abuse & sharing needles * Pre-exposure vaccination HPV (Human papillomavirus), Hepatitis B * Pre- and Post-exposure prophylaxis → HIV **Pre**: if viral load is not suppressed, partner is at risk of infection → to take AV pills continuously **Post**: after possible exposure to virus

Answer 27

Neisseria gonorrhoeae

Answer 28

sexual contact, mother-to-child during childbirth

Answer 29

gram-stain of genital discharge, culture, NAAT

Answer 30

Urethritis → urethra; Cervicitis → cervix; Proctitis → rectal area; Pharyngitis → throat; Conjunctivitis Disseminated → throughout the body

Answer 31

**both** Dysuria Urinary frequency **Male** Purulent urethral discharge **female** Mucopurulent vaginal discharge

Answer 32

**both** disseminated disease **male** Epididymitis Prostatitis urethral stricture **female** Pelvic inflammatory disease Ectopic pregnancy, infertility

Answer 33

**First line** Ceftriaxone: * 500 mg IM single dose for those <150kg * 1g IM single dose for those ≥150kg **Alternative (if ceftriaxone unavailable)** * Gentamicin 240 mg IM in single dose AND * Azithromycin 2g PO in single dose PO doxycycline 100 mg BD x7 days **if chlamydia infection not excluded**

Answer 34

Chlamydia trachomatis

Answer 35

**First line** PO Doxycycline 100 mg BD x7 days **Alternative (if ceftriaxone unavailable)** PO Azithromycin 1g in single dose OR PO levofloxacin 500 mg OD x7 days **Possible to use azithromycin as first line if adherence is of concern**

Answer 36

pregnancy, non-adherence or **symptoms persist** * Need to check for possibility of reinfection

Answer 37

* Sex partners in last 60 days should be evaluated & treated If last sexual exposure >60 days, to treat most recent partner * Abstain from sexual activity for 7 days after treatment to minimise disease transmission * Abstain from sexual intercourse until all sex partners are treated to minimise risk of reinfection

Answer 38

Treponema pallidum

Answer 39

sexual contact, mother-to-child (transplacental during pregnancy)

Answer 40

Darkfield microscopy of exudates from lesions 2 serological tests ⇒ more common

Answer 41

1. trepenomal test 2. non-trepenomal test

Answer 42

* Use treponemal Ag to detect treponemal Ab (produced during infection) * More sensitive & specific than non-treponemal test ⇒ used as confirmatory test * May remain active for life → not for monitoring response to treatment Ab remains present in body; not necessarily indicate current infection

Answer 43

* To determine if infection is CURRENT or PAST * Use nontreponemal Ag (cardiolipin) to detect treponemal Ab * Positive tests → presence of any stage of syphilis * Result reported in quantitative VDRL/ RPR test = **most dilute serum concentration with positive reaction** Result of 1:16 positive ⇒ 1:32 no reaction seen (no Ab at that dilution) * **Higher VDRL/ RPR = greater bacteria presence** (more Ab produced) Ab titre correlate with disease activity ⇒ used to monitor response to treatment * Non-treponemal test titres usually declines after treatment; becomes non-reactive with time

Answer 44

IM Benzathine penicillin G 2.4 million units x1 dose **penicillin allergy** PO doxycycline 100 mg BD x14 days **Counselling** * Take with food to reduce GI upset * Take with glass of water & maintain upright at least 30 mins to prevent heartburn * Do not take with milk, Ca or Fe ⇒ take 2 hours apart **SE** GI, photosensitivity

Answer 45

IM Benzathine penicillin G 2.4 million units once a week x3 dose **penicillin allergy** PO doxycycline 100 mg BD x28 days

Answer 46

IV crystalline (benzyl) penicillin G 3-4 million units q4h or 18-24 million units q24h x10-14 days OR IM procaine penicillin G 2.4 million units OD + PO probenecid 500 mg QID x10-14 days **penicillin allergy** IV/ IM ceftriaxone 2 g OD x10-14 days **Concerns for cross-sensitivity** * Skin prick test to confirm penicillin allergy * To desensitise if necessary (1) Daily low level of exposure of allergen (penicillin) → build up to therapeutic dose (2) Continue at therapeutic dose → if miss dose, should restart low dose again

Answer 47

**IM benzathine** ⇒ released over a week (slower) High sensitivity of syphilis from penG ⇒ low concentration of drug required **IM procaine** ⇒ releases over a day + **IV crystalline** ⇒ high dose Bacteria entering CSF → require high dose of penicillin G to reach CSF concentration

Answer 48

reduces secretion of penicillin ⇒ increases concentration of penicillin in systemic circulation * Cannot give IM procaine alone in neurosyphilis; unable to achieve high enough CSF concentration

Answer 49

Jarisch-Herxheimer reaction = **acute febrile reaction, frequently accompanied by headache, myalgia**, and other symptoms that usually occur **within the first 24 hours after any therapy **for syphilis * **Antipyretics** will help but not prevent

Answer 50

Primary / secondary/ Latent syphilis: Quantitative VDRL/ RPR at 3, **6, 12,** 18 & **24** months (using blood) * treatment success = decrease of VDRL or RPR titre by at least fourfold (ie: 1:64 to 1:16) Neurosyphilis: CSF examination (Quantitative VDRL/ RPR) every 6 month until CSF normal

Answer 51

* show sign & symptoms of disease * Failure to decrease VDRL/ RPR titre by fourfold OR VDRL/ RPR titre increase ie 1:16 to 1:64 * Retreat & re-evaluate for unrecognised neurosyphilis

Answer 52

* All at risk sexual partners should be evaluated for STIs & treat if test positive * Persons receiving syphilis treatment must abstain from sexual contact with new partners **until the syphilis lesions are completely healed**

Answer 53

HSV2 mainly

Answer 54

transfer of body fluids and intimate skin-to-skin contact

Answer 55

Vesicles develop over 7-10 days; heal in 2-4 weeks * Reactivation of virus → will have shorter healing time Intermittent viral shedding from epithelial cells * Possible even when person is asymptomatic * Transmission can occur even without presence of vesicles

Answer 56

1. patient hx 2. virologic testing 3. type-specific serologic test

Answer 57

Previous lesions Sexual contact with similar lesions at genitals

Answer 58

NAAT (PCR) for HSV DNA from genital lesions

Answer 59

Testing for Ab * Ab to HSV develop during the first several weeks after infection & persist indefinitely * Serology is not useful for first episode infection → takes between 6 & 8 weeks for serological detection following a first episode Requires time for buildup of Ab to sufficient concentration for detection Presence of HSV-2 antibody ⇒ anogenital infection

Answer 60

* classical painful multiple vesicular or ulcerative lesions (When vesicles break) * local itching, pain, tender inguinal lymphadenopathy (lymph at inguinal) * Flu-like symptoms (ie: fever, headache, malaise) during first few days after the appearance of lesions

Answer 61

* Prodromal symptoms → mild burning, itching or tingling * Symptoms less severe → less lesions, heal faster, milder symptoms Due to previous immunity; presence of Ab reduces severity

Answer 62

* Warm saline bath → relief discomfort * Analgesia & anti-itch → symptomatic relief * Good genital hygiene → prevent superinfection of bacteria * Counselling about natural history Inform that infection is lifelong + possible transmission even without vesicles; triggers for vesicles + reactivation is possible

Answer 63

acyclovir & valacyclovir **Mechanism of action:** inhibit viral DNA polymerase → inhibit DNA synthesis & replication **Clinical effects:** * Reduce viral shedding by 7 days * Reduce duration of symptoms by 2 days * Reduce time to healing of 1st episode by 4 days **Starting** Maximum benefit ⇒ initiate at earliest stage of disease (within 72 hours)

Answer 64

* PO 400 mg TDS x7-10 days * IV 5-10 mg/kg q8h x2-7 days + PO for 10 days For severe disease/ complications requiring hospitalisation/ herpes encephalitis Usually for immunocompromised (will have higher viral load) **F** = 10-20%; **t1/2** ~3 hours **Counselling** * Take with/ without food After food if have GI upset * Maintain adequate hydration ⇒ prevent crystallisation in renal tubules **SE (general, non-specific)** Malaise, headache, N/V/D

Answer 65

PO 1g BD x7-10 days L-valine ester of acyclovir (prodrug) Rapidly & almost completely converted to acyclovir & valine **F** = 55%; **t1/2** ~3 hours * Can give higher dose & less frequently **Counselling**: similar to acyclovir including hydration **SE**: mainly headache

Answer 66

Median = 4 recurrences the year after first symptomatic episode

Answer 67

1. chronic suppressive therapy 2. episodic therapy

Answer 68

PO Acyclovir 400 mg BD PO valacyclovir 1 g OD

Answer 69

* patients who have many recurrences * Patients with complicated disease course (ie disseminated disease) * immunocompromised hosts → may have severe disease state during reactivation of HSV

Answer 70

* reduces the frequency of recurrences by 70%–80% in patients who have frequent recurrences (ie: >6 recurrences per year) * Most will have no symptomatic outbreaks ⇒ improved QOL * decreased risk of transmission in combination with consistent condom use & abstinence during recurrences Reduction in chance of viral shedding + barrier method

Answer 71

Cost → daily dosing Compliance → continuous dosing

Answer 72

when patient have prodromal symptoms OR vesicles present

Answer 73

Either one of the following: * PO Acyclovir 800 mg BD x5 days OR TDS x2 days * PO valacyclovir 500 mg BD x3 days * PO valacyclovir 1 g OD x5 days

Answer 74

* **Shorten duration & severity** of symptoms * **Less costly** compared to chronic suppression * Patient more likely to be **compliant**

Answer 75

* Requires initiation of therapy within 1 day of lesion onset or during the prodrome that precedes some outbreaks * Does not reduce risk of transmission Once patient is off AV → can shed virus & transmit HSV

Answer 76

* **Symptomatic** sex partners: evaluated & treated in the same manner as patients who have genital lesions. * **Asymptomatic** sex partners of patients who have genital herpes should be **questioned concerning histories of genital lesions**, encouraged **to examine themselves for lesions and seek medical attention early if lesions occur**.

IC18 STI Flashcards

(102 cards)