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BASIC - INFECTIOUS DISEASES Flashcards

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1
Q

Indications of phenomethylpenicillin?

A

o Oral infections, tonsillitis, otitis media, cellulitis, erysipelas
o Prevention of pneumococcal in asplenia/sickle cell disease
o Prevention of recurrence of rheumatic fever
o Acute sinusitis

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2
Q

Indications of benzylpenicillin?

A

o Throat infections, otitis media, cellulitis, pneumonia, endocarditis, anthrax
o Intrapartum prophylaxis of Group-B strep
o Meningitis, meningococcal disease

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3
Q

Mechanism of action of penicillin?

A
  • Inhibit enzyme responsible for cross-linking peptidoglycan in bacterial cell walls
  • Weakens cell walls, preventing maintenance of osmotic gradient
  • Cell swells, lysis and dies
  • Penicillins contain B-lactam ring
  • Bacteria resist actions of penicillins by making B-lactamase, limiting intracellular concentration of penicillin or change target enzyme to prevent binding
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4
Q

Side effects of penicillins?

A
  • Diarrhoea, nausea, vomiting
  • Allergy in 1-10% of people
    o Skin rash 7-10 days after first exposure or 1-2 days after repeat exposure (IgG subacute)
    o IgE anaphylactic reaction (0.05%) – hypotension, bronchial and laryngeal spasm, angioedema
  • CNS toxicity in high doses or renal impairment
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5
Q

Contraindications in penicillins?

A
  • History of allergy
  • Renal impairment
    o Dose reduction in benzylpenicillin
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6
Q

Interactions of penicillins?

A
  • Reduce renal excretion of methotrexate – risk of toxicity
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7
Q

Routes of phenoxymethylpenicillin and benzylpenicillin?

A
  • Benzylpenicillin – only IV/IM as hydrolysis by gastric acid prevents absorption
    o Severe infections at high dose only
  • Pen V – orally taken
  • Short half-life so given every 4-6 hours
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8
Q

Indications of amoxicillin & co-amoxiclav?

A
  • CAP, acute bronchiectasis, acute exacerbation of COPD, acute otitis media, sinusitis
  • UTI (other alternatives)
  • Combination for hospital-acquired infection or intra-abdominal sepsis
  • H.pylori eradication
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9
Q

Mechanism of amoxicillin & what addition does co-amoxiclav have?

A
  • Inhibit enzyme responsible for cross-linking peptidoglycan in bacterial cell walls
  • Weakens cell walls, preventing maintenance of osmotic gradient
  • Cell swells, lysis and dies
  • Penicillins contain B-lactam ring
    o Addition of amino group – increases activity against aerobic Gram-negative bacteria – broad spectrum
    o Addition of B-lactamase inhibitor clavulanic acid increases spectrum of antimicrobial activity further (S.aureus and gram-negative anaerobes)
  • Bacteria resist actions of penicillins by making B-lactamase, limiting intracellular concentration of penicillin or change target enzyme to prevent binding
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10
Q

Side effects of amoxicillin/co-amoxiclav?

A
  • Diarrhoea, nausea, vomiting
  • Antibiotic-associated colitis
    o Broad spectrum antibiotics kill normal gut flora and C.diff grows
    o Debilitating and can cause colonic perforation
  • Cholestatic jaundice (co-amoxiclav)
  • Allergy in 1-10% of people
    o Skin rash 7-10 days after first exposure or 1-2 days after repeat exposure (IgG subacute)
    o IgE anaphylactic reaction (0.05%) – hypotension, bronchial and laryngeal spasm, angioedema
  • CNS toxicity in high doses or renal impairment
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11
Q

Dose changes in renal impairment in amoxcillin/co-amoxiclav?

A

o Dose reduction (crystalluria)

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12
Q

Interactions of amoxicillin/co-amoxiclav?

A
  • Reduce renal excretion of methotrexate – risk of toxicity
  • Enhance anticoagulant effect of warfarin by killing gut flora that synthesise vitamin K
  • DO NOT GIVE IN EBV
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13
Q

Dose of amoxicillin?

A
  • IV should be switched to oral after 48h if indicated

- Oral amoxicillin usually 500mg 8-hourly for 7-14 days

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14
Q

Indications of flucloxacillin?

A
  • Otitis externa, impetigo, cellulitis, endocarditis, osteomyelitis, surgical prophylaxis
  • Prevention of S.aureus infection in cystic fibrosis
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15
Q

Mechanism of flucloxacillin?

A
  • Inhibit enzyme responsible for cross-linking peptidoglycan in bacterial cell walls
  • Weakens cell walls, preventing maintenance of osmotic gradient
  • Cell swells, lysis and dies
  • Penicillins contain B-lactam ring
    o Acyl side chain protect B-lactam ring from B-lactamases
     Effective against B-lactamase producing staphylococci
     MRSA resists flucloxacillin action by reducing penicillin binding affinity
  • Bacteria resist actions of penicillins by making B-lactamase, limiting intracellular concentration of penicillin or change target enzyme to prevent binding
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16
Q

Side effects of flucloxacillin?

A
  • Liver toxicity – cholestasis and hepatitis
  • Allergy in 1-10% of people
    o Skin rash 7-10 days after first exposure or 1-2 days after repeat exposure (IgG subacute)
    o IgE anaphylactic reaction (0.05%) – hypotension, bronchial and laryngeal spasm, angioedema
  • CNS toxicity in high doses or renal impairment
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17
Q

Contraindications of flucloxacillin?

A
  • History of allergy

- Prior flucloxacillin-related hepatotoxicity

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18
Q

Dose changes in renal impairment of flucloxacillin?

A

o Dose reduction if <10eGFR

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19
Q

Interactions of flucloxacillin?

A
  • Reduce renal excretion of methotrexate – risk of toxicity
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20
Q

Dose of flucloxacillin?

A
  • IV high dose 1-2g 4-6 hourly for severe infections
  • Osteomyelitis and endocarditis require 6 weeks of high-dose IV
  • Oral flucloxacillin 250-500mg 4 times a day
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21
Q

Indications of Tazocin?

A
  • For severe infections
    o HAP, sepsis, acute COPD/bronchiectasis
    o Complicated UTI, skin, soft-tissue infections
  • Neutropenic sepsis
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22
Q

Mechanism of Tazocin?

A
  • Inhibit enzyme responsible for cross-linking peptidoglycan in bacterial cell walls
  • Weakens cell walls, preventing maintenance of osmotic gradient
  • Cell swells, lysis and dies
  • Penicillins contain B-lactam ring
    o Side chain of broad-spectrum antibiotics converted to form urea
     Increases affinity including pseudomonas aeruginosa
    o B-lactamase inhibitor tazobactam confers activity against S.aureus and Gram-neg anaerobes
  • Bacteria resist actions of penicillins by making B-lactamase, limiting intracellular concentration of penicillin or change target enzyme to prevent binding
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23
Q

Side effects of Tazocin?

A
  • Diarrhoea, nausea, vomiting
  • Antibiotic-associated colitis
    o Broad spectrum antibiotics kill normal gut flora and C.diff grows
    o Debilitating and can cause colonic perforation
  • Allergy in 1-10% of people
    o Skin rash 7-10 days after first exposure or 1-2 days after repeat exposure (IgG subacute)
    o IgE anaphylactic reaction (0.05%) – hypotension, bronchial and laryngeal spasm, angioedema
  • CNS toxicity in high doses or renal impairment
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24
Q

Dose changes in renal impairment of Tazocin?

A

o Max 4.5g every 8 if eGFR 20-40

o Max 4.5g every 12 hours if eGFR <20

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25
Cautions of Tazocin?
o Risk of C.diff infection
26
Interactions of Tazocin?
- Reduce renal excretion of methotrexate – risk of toxicity | - Enhance anticoagulant effect of warfarin by killing gut flora that synthesise vitamin K
27
Dose of Tazocin?
- IV infusion only | - Usual dose of 4.5g, given every 6-8 hours
28
Names of carbapenems?
Meropenem | Ertapenem
29
Indications of carbapenems?
- IV reserved for severe infections
30
Mechanism of carbapenems?
- Naturally occurring antimicrobials produced by fungi and bacteria - B-lactam ring - Inhibit enymes responsible for cross-linking peptidoglycans in bacterial cell walls - Weakens walls and causes bacterial cell swelling, lysis and death - Broad spectrum - Hydroxyethyl Ring – resistant to B-lactamases
31
Side Effects of carbapenems?
- Diarrhoea, nausea, vomiting - Antibiotic-associated colitis o Broad spectrum antibiotics kill normal gut flora and C.diff grows o Debilitating and can cause colonic perforation - Allergy in 1-10% of people o Skin rash 7-10 days after first exposure or 1-2 days after repeat exposure (IgG subacute) o IgE anaphylactic reaction (0.05%) – hypotension, bronchial and laryngeal spasm, angioedema - CNS toxicity in high doses or renal impairment
32
Cautions of carbapenems?
o Risk of C.diff infection | o Epilepsy
33
Dose changes in renal impairment of carbapenems?
o Dose reduction
34
Interactions of carbapenems?
- Enhance anticoagulant effect of warfarin by killing gut flora that synthesise vitamin K - Reduce plasma concentrations and efficacy of valproate
35
Dose of meropenems?
- IV only | - Meropenem 1-2g IV 8-hourly
36
Names of cephalosporins?
Cephalexin, cefuroxime, cefotaxime, ceftriaxone, ceftazidime and ceftaroline
37
Indications of cephalosporins?
- 2nd and 3rd line treatment for urinary and respiratory tract infections - IV reserved for severe infections
38
Mechanism of cephalosporins?
- Naturally occurring antimicrobials produced by fungi and bacteria - B-lactam ring - Inhibit enymes responsible for cross-linking peptidoglycans in bacterial cell walls - Weakens walls and causes bacterial cell swelling, lysis and death - Broad spectrum - Dihydrothiazine Ring – resistant to B-lactamases
39
Side effects of cephalosporins?
- Diarrhoea, nausea, vomiting - Antibiotic-associated colitis o Broad spectrum antibiotics kill normal gut flora and C.diff grows o Debilitating and can cause colonic perforation - Allergy in 1-10% of people o Skin rash 7-10 days after first exposure or 1-2 days after repeat exposure (IgG subacute) o IgE anaphylactic reaction (0.05%) – hypotension, bronchial and laryngeal spasm, angioedema - CNS toxicity in high doses or renal impairment
40
Contraindications and cautions of cephalosporins?
Contraindication - History of allergy to penicillins, cephalosporins or carbepenems Caution o Risk of C.diff infection
41
Dose changes in renal impairment of cephalosporins?
o Half dose in eGFR <5
42
Interactions of cephalosporins?
- Enhance anticoagulant effect of warfarin by killing gut flora that synthesise vitamin K - Increase nephrotoxicity of aminoglycosides
43
Dose of cefotaxime?
- Usually over 6-12 hourly | - Cefotaxime 2g IV 6-hourly for bacterial meningitis
44
Names of aminoglycosides?
Gentamicin, amikacin
45
Indications of aminoglycosides?
- Severe infections, particularly Gram-negative aerobes o Severe sepsis o Pyelonephritis and complicated UTI o Biliary and other intra-abdominal sepsis o Endocarditis o Bacterial eye infections - Lack activity against streptococci and anaerobes
46
Mechanism of aminoglycosides?
- Bind irreversibility to bacterial ribosomes (30S subunit) and inhibit protein synthesis - Bactericidal - Enters bacterial cells via oxygen-dependent transport system - Spectrum – gram-negative aerobic bacteria, staphylococci and mycobacteria
47
Side effects of aminoglycosides?
- Nephrotoxicity and ototoxicity o Accumulate in renal tubular epithelial cells and cochlear hair cells triggering cell death - Tinnitus
48
Contraindications of aminoglycosides?
- Impair neuromuscular transmission so avoid in Myasthenia gravis - Caution o Elderly, neonates, renal impairment
49
Interactions of aminoglycosides?
- Ototoxicity increases with loop diuretics or vancomycin | - Nephrotoxicity increases with ciclosporin, platinum, cephalosporins or vancomycin
50
Prescription of gentamicin?
- IV only given over an hour - Dose calculated using patients’ weight and renal function (IBW = 7mg/kg) o Use patient’s height to select IBW, if ABW less than IBW – use dose according to ABW - Dose interval determined by drug level monitoring, usually 24 hours but longer in renal impairment - Often single dose course
51
Initial monitoring in gentamicin?
o One 10ml blood sample between 6-14 hours after start of first infusion o Plain tube (clotted blood) – record exact time taken o Plot of normogram o Dose interval according to value given off graph – if 24,36 or 48h o If level is over 48h dosing interval STOP treatment and take daily levels – gentamicin can be restarted once below 2mg/L
52
Repeat monitoring in gentamicin?
o U&Es and creatinine daily  If creatinine rising >20% and still between 6-14 hours – measure gentamicin levels  If not between 6-14 hours – contact microbiology o Repeat Gentamicin levels according to dosage interval:  Dosage level - 24 hours = 3 days  Dosage level - 36 hours = 3 days  Dosage level - 48 hours = 2 days
53
Names of macrolides?
Clarithromycin, Erythromycin, Azithromycin
54
Indications of macrolides?
- Treatment of respiratory and soft tissue infections as alternative to penicillin - Severe pneumonia (added to cover atypicals like Legionella, Mycoplasma) - Eradication of H.pylori
55
Mechanism of macrolides?
- Inhibit bacterial protein synthesis – bind to 50S subunit and block translocation - Bacteriostatic
56
Side effects of macrolides?
- Irritant – causing nausea, vomiting, abdominal pain and diarrhoea when taken orally, thrombophlebitis if IV - Antibiotic-associated colitis (C.diff) - Cholestatic jaundice - Prolongation of QT interval - Ototoxicity at high doses
57
Contraindications of macrolideS?
- Hepatic elimination mostly – caution in severe hepatic impairment and dose reduction in severe renal impairment
58
Interactions of macrolides?
- Erythromycin and Clarithromycin inhibit CYP450 enzymes - Caution with drugs that prolong QT o Amiodarone, antipsychotics, quinine, quinolone, antibiotics and SSRIs
59
Common dose of macrolides?
- Oral dosage 250-500mg BDS for 7-14 days
60
What class of drug is clindamycin?
Semisynthetic Lincosamide
61
Indications of clindamycin?
- Treatment of staphylococcal bone and joint infections - Peritonitis - Intrabdominal sepsis - Falciparum malaria - Bacterial vaginosis - Acne Vulgaris
62
Mechanisms of clindamycin?
- Inhibit bacterial protein synthesis – bind to 50S subunit and block translocation - Bacteriostatic
63
Side effects of clindamycin?
- Skin reactions - Abdominal pain - Antibiotic-associated colitis - Diarrhoea
64
Contraindications of clindamycin?
- Diarrhoeal states
65
Interactions of clindamycin?
- Increases effects of actracurium, mivacurium, pancuronium, rocuronium, suxamethonium so caution
66
Dose of clindamycin?
- Oral dosage 150-300mg QDS up to 450mg
67
Important patient information given in clindamycin?
o Damages latex condoms with vaginal use
68
Names of glycopeptides?
Vancomycin, Teicoplanin
69
Indications of glycopeptides?
- Treatment of Gram-positive infections – bone, joint, CAP, HAP, meningitis, endocarditis if penicillins can’t be used - Antibiotic associated colitis (C.diff)
70
Mechanism of glycopeptides?
- Inhibits growth and cross-linking of peptidoglycan chains, inhibiting synthesis of cell wall of Gram-positive bacteria
71
Side effects of glycopeptides?
- Thrombophlebitis at infusion site - Anaphylactoid reactions o Red man syndrome – generalised erythema, hypotension and bronchospasm o Not true allergy but due to non-specific degranulation of mast cells - Allergy - IV Vancomycin o Nephrotoxic (renal failure and interstitial nephritis) o Ototoxic (tinnitus and hearing loss) o Neutropenia and thrombocytopenia
72
Caution of glycopeptides?
- Monitoring of plasma concentrations and dose adjustment - Caution o Renal impairment (serial renal function monitoring) o Elderly
73
Interactions of glycopeptides?
- Ototoxicity/nephrotoxicity increases with aminoglycosides, loop diuretics or ciclosporin
74
Dose of glycopeptides?
o Initial loading dose determined by actual body weight (in glucose 5% or NaCl 0.9%)  <60kg = 1g  60-90kg = 1.5g  >90kg = 2g
75
Monitoring of vancomycin? | How is maintenance level calculated?
o Maintenance dose & dosing interval calculated using patient’s creatinine clearance (keeps trough levels of 10-15mg/L) o Monitor pre-dose trough levels at 36-48 hours (should be between 10-20mg/L)
76
How to adjust maintenance dose of vancomycin?
 If <5 – move up to two dosing levels from current dosing schedule  If 5-10 – move up 1 or 2 levels depending on target (10-15 or 15-20)  If 10-20 – continue at current dose  If 20-25 – Move down one dosing level  IF >25 – omit next dose & decrease by two dosing levels  If >30 – seek pharmacy advice
77
Monitoring during vancomycin levels?
o Daily U&Es and creatinine | o Regular FBC during prolonged therapy
78
Common dose for vancomycin?
- IV only given | - For C.diff – 125mg 6-hourly for 10-14 days
79
Indications of metronidazole?
- Anaerobic infections in: o Antibiotic-associated colitis (C.diff) o Oral infections (dental abscess) or aspiration pneumonia o Surgical and gynaecological infections o Protozoal infections (BV, trichomonas, giardiasis) o H.pylori eradication
80
Mechanism of metronidazole?
- Enter bacterial cells via passive diffusion - In anaerobic bacteria, reduction of metronidazole generates nitroso free radicals that bind to DNA and cause DNA degradation and cell death
81
Side effects of metronidazole?
- Dry mouth, metallic taste - Nausea and vomiting - Diarrhoea - Immediate or delayed hypersensitivity reactions - High doses/prolonged course o Peripheral or optic neuropathy o Seizures o Encephalopathy
82
Cautions of metronidazole?
o Renal impairment (serial renal function monitoring) | o Elderly
83
Interactions of metronidazole?
- Metabolised by CYP450 enzymes – dose reduction in severe liver impairment - Some inhibitory effect on CYP450 enzymes - Inhibits acetaldehyde dehydrogenase – responsible for clearing alcohol so no alcohol when on metronidazole o Gives disulfiram reaction (flushing, nausea, headache, vomiting) - Increased risk of lithium toxicity
84
Typical dose of metronidazole?
- Oral typical and starting dose is 400mg 8-hourly | - Can be prescribed IV, rectally, topical, vaginal
85
Monitoring of metronidazole?
o If treatment >10 days measure: |  FBC and LFTs
86
Important communication to patients of metronidazole?
o No alcohol during or 48 hours after metronidazole treatment
87
Indications of nitrofurantoin?
- Uncomplicated UTI | - Prophylaxis in recurrent, catheter-associated or surgical prophylaxis of UTI
88
Mechanism of nitrofurantoin?
- Metabolised (reduced) in bacterial cells by nitrofuran reductase - Active metabolite damages bacterial DNA and causes cell death
89
Side effects of nitrofurantoin?
- N & V, diarrhoea - Immediate or delayed hypersensitivity reactions - Turn urine dark yellow/brown - Pneumonitis, hepatitis, peripheral neuropathy - Neonates – haemolytic anaemia
90
Contraindications of nitrofurantoin?
o Porphyria, G6PD deficiency o Infants <3m o Pregnancy 3rd trimester o Renal Impairment
91
Dose change in renal impairment of nitrofurantoin?
o Avoid if <45 eGFR
92
Typical dose in UTI of nitrofurantoin? And dose of prophylactic?
- Acute UTI – 50-100mg QDS either 3 day (uncomplicated women) or 7 days (men or more complicated women) - Prevention of recurrent UTI – single nightly dose of 50-100mg
93
Monitoring of nitrofurantoin?
o Long term therapy: LFT, pulmonary symptoms
94
Names of quinolones?
Ciprofloxacin, Moxifloxacin, Levofloxacin
95
Indications of quinolones?
- 2nd or 3rd generation due to resistance and C.diff o UTI o Severe GI infection – Shigella, campylobacter o LRTI
96
Mechanism of quinolones?
- Inhibit DNA synthesis | - Rapid resistance can develop though
97
Side effects of quinolones?
- N&V, diarrhoea - Oesophageal irritation - Lower seizure threshold - Hallucinations - Rupture of muscle tendons - Prolong QT interval - C.diff Colitis
98
Contraindications of quinolones?
o Hx of tendon disorders | o Pregnancy
99
Cautions of quinolones?
o Risk of seizures | o Risk factors for QT prolongation
100
Dose changes in renal impairment of quinolones?
o Reduce dose if eGFR <60
101
Interactions of quinolones?
- Drugs containing divalent cations reduce absorption of quinolones - Inhibits CYP450 enzymes - Avoid in drugs that prolong QT: o Amiodarone, antipsychotics, quinine, macrolides, SSRIs
102
Typical dose of ciprofloxacin?
- Ciprofloxacin typically 250-750mg orally 12-hourly or 400mg IV 12-hourly
103
Names of tetracyclines?
Doxycycline, lymecycline, Tigecycline
104
Indications of tetracyclines?
- Acne vulgaris and rosacea - LRTIs including exacerbation of COPD, pneumonia and atypical pneumonia - Chlamydia, Syphilis, and PID - Typhoid anthrax, malaria and Lyme Disease
105
Mechanism of tetracyclines?
- Inhibits bacterial protein synthesis by binding to ribosomal 30S subunit - Prevents transfer of tRNA to mRNA – bacteriostatic
106
Sides effects of tetracyclines?
- N, V and diarrhoea - Oesophageal irritation - Photosensitivity - Discolouration and/or hypoplasia of tooth enamel in children - Intracranial hypertension
107
Contraindications of tetracyclines?
o Pregnancy o Breastfeeding o Children <12 years old
108
Dose changes in renal impairment of tetracyclines?
o Avoid – raise plasma urea
109
Interactions of tetracyclines?
- Bind to divalent cations o Do not give within 2 hours of Ca, antacids, iron - Enhance anticoagulant effect of warfarin
110
Dose of doxycycline?
- Oral typically 100-200mg daily
111
Indications of trimethoprim?
- Uncomplicated UTI | - Co-trimoxazole (trimethoprim and sulfamethoxazole) - PCP in HIV
112
Mechanism of trimethoprim?
- Inhibits bacterial folate synthesis, bacteriostatic | - However, widespread resistance in areas of UK
113
Side effects of trimethoprim?
- Nausea and vomiting - Diarrhoea - Hypersensitivity reactions – anaphylaxis, drug fever, erythema multiforme - Megaloblastic anaemia, leukopenia and thrombocytopenia - Hyperkalaemia and elevate creatinine concentrations
114
Contraindications of trimethoprim?
o Blood dyscrasias | o 1st trimester of pregnancy (folate antagonist associated with foetal abnormalities (CV defects, oral cleft))
115
Dose change in renal impairment of trimethoprim?
o Dose reduction – half dose after 3 days if eGFR 15-30, half dose if <15 eGFR
116
Interactions of trimethoprim?
- Elevates potassium in conjunction with: o Aldosterone antagonists, ACE inhibitors, ARBs - Risk of haematological effects increased with: o Methotrexate, phenytoin - Enhance anticoagulant effect of warfarin
117
Usual dose of trimethoprim? And prophylactic dose?
- Acute UTI – 200mg BDS either 3 day (uncomplicated women) or 7 days (men or more complicated women) - Prevention of recurrent UTI – single nightly dose of 100mg
118
Monitoring of trimethoprim?
o Long term therapy: FBC
119
Names of common antifungals?
Clotrimazole (Nystatin), Fluconazole
120
Indications of azoles?
- Local fungal infections of oropharynx, vagina or skin (topical or oral) - Systemic treatment of invasive fungal infections
121
Mechanism of azoles?
- Antifungals bind to ergosterol in fungal cell membranes, creating polar pore which allows intracellular ions to leak out - Imidazole (clotrimazole) and triazole (fluconazole) inhibit ergosterol synthesis, impairing cell membrane synthesis and replication
122
Side effects of topical azoles and fluconazole?
- Topical – local irritation where applied - Fluconazole o GI upset (nausea, vomiting, diarrhoea, abdominal pain) o Headache o Hepatitis o Hypersensitivity causing skin rash - Rarely: o Severe hepatic toxicity o Prolonged QT interval
123
Contraindications of fluconazole?
o Pregnancy
124
Cautions in fluconazole?
o Risk factors for QT prolongation | o Hepatic Impairment
125
Dose changes in renal impairment in fluconazole?
o Reduce dose if eGFR <50
126
Interactions with fluconazole?
o Inhibits CYP450 enzymes o Reduce antiplatelet actions of clopidogrel o Risk of arrhythmias in drugs that prolong QT  Amiodarone, antipsychotics, quinine, quinolone, macrolides and SSRIs
127
Prescriptions of nystatin, clotrimazole & fluconazole?
o Nystatin – topical or oral – thrush - 100,000 units QDS for 7 days or 48h after lesions resolve o Clotrimazole – 1% cream applied BDS/TDS o Fluconazole – Oral 150mg single dose
128
Indications of aciclovir?
- Herpes Simplex Infection - VZV - Herpes Zoster Virus
129
Mechanism of aciclovir?
- Converted by thymidine kinase to acyclovir monophosphate which inhibits HSV-specific DNA polymerases and prevents synthesis
130
Side effects of aciclovir?
- Oral – abdominal pain, diarrhoea, headache, nausea and vomiting o Rarely encephalopathy, neutropenia, leukopenia, thrombocytopenia - Topical – dry skin, stinging sensation
131
Dose changes in renal impairment of aciclovir?
o Maintain adequate hydration | o Dose reduction if eGFR <10
132
Interactions of aciclovir?
- Increases exposure to aminophylline and theophylline so adjust dose
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