Abx Prescribing Pathways Flashcards
https://www.bnf.org/wp-content/uploads/2022/03/summary-antimicrobial-prescribing-guidance_mar-22_v0.2.pdf?UNLID=9554059142022101301458
What other Abx does a penicillin-allergic pt need to avoid?
- There’s cross-sensitivity with cephalosporins and other B-lactam Abx.
- Good alts, would be macrolides AND metronidazole in dental infection
In pregnancy what is the safest Abx?
Penicillin or cephalosporins
In pregnancy, which Abx should you avoid?
- C/I = tetracyclines and trimethoprim
- Nitrofurantoin causes N, thus, avoid at term
AVOID: (MCAT) - metronidazole, chloramphenicol, aminoglycosides, tetracycline
- quinolones
- sulphonamides
Human and animal bites
1st line: Co-amoxiclav 250mg/125mg or 500/125mg TDS
2nd: Doxycycline 200mg on day 1, then 100mg or 200md OD AND Metronidazole 400mg TDS
Prophylaxis: 3 days
Treatment: 5 days
Human and animal scratches: Flucloxacillin
Tick bites (can cause Lyme disease)
1st: Doxycycline 100mg BD for 21 days of treatment
2nd: Amoxicillin 100mg TDS
Diabetic foot infection - MILD (less than 2cm)
- Flucloxacillin 500mg to 1g QDS for 7 days
- If penicillin allergy, clarithromycin 500mg BD, erythromycin (in pregnancy) 500mg QDS, doxycycline 200mg on day 1 and then 100mg OD.
Diabetic foot infection - Moderate/Severe (abscess, osteomyelitis - infection that causes pain in the longs bones in the leg)
- Flucloxacillin or co-amoxiclav +/- gentamicin
- Penicillin allergy => Co-trimoxazole +/- gentamicin
Cellulitis
1st line: Flucloxacillin 500mg to 1g QDS for 5 - 7 days
Cellulitis - penicillin allergy or if flucloxacillin unsuitable?
- clarithromycin 500mg BD or erythromycin (in pregnancy) 500mg QDS
- doxycycline 200mg on day 1 then 100mg OD
- co-amoxiclav 500mg/125mg TDS for children
Cellulitis - for infections near eyes or nose
- Co-amoxiclav
- Penicillin allergic => Clarithromycin AND Metronidazole
CAP - low severity - 5 days
C - confusion?
U - Urea > 7mmol/L
R - RR > or = 30/min
B - BP at <90mmHg for systolic, and < or = 60mmHg diastolic
65 - > or = 65 years
1st line: Amoxicllin 500mg TDS for 5 days
2nd: Doxycycline 200mg on day 1, then 100mg OD or clarithromycin 500mg BD (erythromycin 500mg QDS in pregnancy)
CAP - moderate severity - 5 days
1st: Amoxicllin AND (if atypical pathogens suspected) clarithromycin (erythromycin in pregnancy)
2nd: Doxycyline or Clarithromycin
CAP - high severity - 5 days
1st: Co-amoxiclav 500/125mg TDS AND clarithromycin 500mg BD (erythromycin 500mg QDS in pregnancy)
2nd: Levofloxacin
Diarrhoea - C.difficile?
10 days treatment
1st line: Vancomycin
2nd: Fidaxomicin
Life threatening: Vancomycin AND IV Metronidazole
Diarrhoea - traveller’s diarrhoea?
Standby: Azithromycin 500mg OD for 1 to 3 days
Prophylaxis/Treatment: Bismuth Subsalicylate
Infective Diarrhoea
If Campylobacter suspected - Clari 250mg - 500mg BD for 5 - 7 days
If Gardia suspected - Tinidazole 2g single dose
Ear infections - Otitis Externa
1st: Topical acetic acid 2%
2nd: Topical neomycin sulphate with corticosteroid (usually hydrocortisone)
If systemic treatment needed, i.e. cellulitis: Flucloxacillin
Ear infections - Otitis media
1st: Amoxicillin for 5 to 7 days
2nd: (worsening symptoms despite 2 - 3 days treatment) Co-amoxiclav
Penicillin allergy: Clarithromycin, erythromycin in pregnancy
Under 18s:
1st topical: Phenazone 40mg/g with lidocaine 10mg/g - 4 drops BD/TDS for 7 days
H. Pylori
Triple therapy:
- PPI: Omeprazole, esmoprazole, lansoprazole etc.
If omeprazole is given with clopidogrel => give lanosprazole instead!
- 2 x Abx: Amoxicillin 1000mg BD and Clarithromycin 500mg BD or Metrondazole 400mg BD for 7 days
OR Metronidazole 400mg BD and Clarithromycin 500mg BD for 7 days
Amoxicillin tends to be included in triple therapy unless penicillin allergy
H. Pylori - 13C Breath test
Helicobacter Pylori is diagnosed by Urea (13C) Breath Test.
- PPI use: It shouldn’t be performed within 2 WEEKS of taking PPIs
- Abx: Shouldn’t be performed within 4 WEEKS of taking Abx
HAP - non-severe - 5 days then review
1st: Co-amoxiclav 500mg/125mg TDS
2nd: (adults) doxycycline 200mg on day 1 then 100mg OD (teeth deposits, bone deposits, discoloration of teeth - avoid in age 12 and below) OR cefalexin 500mg BD or TDS OR co-trimoxazole 960mg BD OR levofloxacin
2nd: (children) clarithromycin
Impetigo - localised non-bullous
1st: Hydrogen peroxide 1% BD/TDS for 5 days
2nd: Fusidic acid 2% TDS for 5 days or (mupirocin 2% TDS if fusidic acid resistance suspected)
Impetigo - widespread non-bullous
Widespread - upper lip, chin and nose
1st: Fusidic acid 2% TDS for 5 days (mupirocin 2% if resistance suspected)
Impetigo - bullous or patients who are systemically unwell
1st: flucloxacillin 500mg QDS
2nd: clarithromycin 250mg QDS (erythromycin in pregnancy)
Lower UTIs - MEN
1st: nitrofurantoin 100mg MR BD (if eGFR > 45mL/min) or trimethoprim 200mg BD if low resistance risk
7 days treatment in men
Lower UTIs - NON-PREGNANT WOMEN
1st: nitrofurantoin 100mg MR BD (if eGFR > 45 mL/min) or trimethoprim 200mg BD (if low resistance risk)
2nd: pivmecillinam or fosfomycin
Uncomplicated: 3 days treatment
Lower UTI - PREGNANT WOMEN
1st: nitrofurantoin (if eGFR > 45mL/min and avoid at term)
2nd: Cefalexin 500mg BD or amoxicillin 500mg TDS
Pregnancy: 7 days treatment
For lower UTIs, for which types of patients does it need to be 7 days treatment?
Men
Pregnant people
Catheter associated
When should you avoid using nitrofurantoin in terms of eGFR?
eGFR < 45mL/min
Strep throat and Scarlett fever
1st: phenoxymethylpenicillin 500mg QDS for 10 days (take on an empty stomach 1h before food and 2h after food)
2nd: clarithromycin, erythromycin in pregnancy
What are the symptoms to scarlet fever?
- flu like symptoms, high temperature, swollen neck glands
- red rash with small raised bumps, feels rough like sandpaper
- white coating on tongue that can lead to a “strawberry” tongue
Acne Vulgaris
Review first line treatment after 12 weeks!
ACNE OF ANY SEVERITY:
- fixed combo of topical adapalene with topical benzyl peroxide => not for under 9yo
OR
- fixed combination of topical clindamycin or topical tretinoin => not for under 12yo
MILD - MODERATE ACNE:
- fixed combination of topical clindamycin with topical benzoyl peroxide => not for under 12s; mild-moderate acne
MODERATE - SEVERE ACNE:
- fixed combination of topical adapalene with topical benzyl peroxide AND either PO lymecycline or PO doxycycline => not for under 12s; moderate-severe acne
Bacterial vaginosis (strong fishy smell) and trichomoniasis (thick, thin or frothy and yellow-green in colour)
Metronidazole 400mg BD for 7 days
Chlamydia
1st: Doxycycline 100mg BD for 7 days
2nd: azithromycin 1000mg STAT then 500mg OD for 2 days (3 days in total)
Conjunctivitis and blepharitis
Conjunctivitis:
1st: chloramphenicol 2hourly for 2 days, then reduce frequency to TDS-QDS
2nd: (1st line is CI, e.g. pregnant) Fusidic acid 1% eye drops — apply 1 drop BD. Continue use until 48 hours after the infection has cleared.
Blepharitis:
1st: topical chloramphenicol 1% ointment BD
Dental abscess
1st: amoxicillin 500mg TDS for 5 days OR phenoxymethylpenicillin 500mg QDS for 5 days OR metronidazole 400mg TDS for 5 days
Gonorrhoea
Ceftriaxone 1g IM OR Ciprofloxacin 500mg STAT
Meningitis
Benzylpenicillin IV or IM (if vein can’t be accessed)
- kid <1 year 300mg
- kid 1 - 9 years: 600mg
- adult/kid 10+: 1.2g
Causative agent: Neisseria meningitidis
or if history of allergy to penicillin
IV (IM if venous access not available) Cefotaxime injection (1 g)
NEONATE 50 mg/kg
CHILD 1 MONTH–11 YEARS 50 mg/kg (max. 1 g)
CHILD 12–17 YEARS 1 g
ADULT 1 g
or if history of immediate hypersensitivity reaction (including anaphylaxis, angioedema, urticaria, or rash immediately after administration) to penicillin or to cephalosporins
IV Chloramphenicol injection (1 g)
CHILD 12.5–25 mg/kg
ADULT 12.5–25 mg/kg
Scabies - red spots with silvery interlinking lines, usually in webbing of fingers / toes
1st: Permethrin 5% cream
2nd: Malathion 0.5% aq liquid if permethrin allergic
Apply OW for 2 doses => 1 WEEK APART
Apply to the whole body INCLUDING SCALP, NECK, FACE AND EARS
Treat ALL members of the family and avoid physical contact with other members of the family
Home/sexual contacts => treat within 24h
Headlice
Wet combing = comb for 30min at 4-day intervals until no lice found for 3 sessions (min. 2 weeks)
DIMETICONE = apply for 8h to dry naturally - repeated AFTER 7 days
MALATHION = apply for 12h to dry naturally - repeated AFTER 7 days
- AVOID in severe eczema or asthma due to alcohol contents
BENZYL BENZOATE and PERMETHRIN - not recommended
MHRA = some preps are flammable!
Sinusitis
1st: phenoxymethylpenicillin 500mg QDS for 5 days
2nd: penicillin allergic - doxycycline 200mg on day 1, then 100mg OD for 5 days
Acute Cough
Adults:
- 1st line: DOXY 200mg on day 1, then 100mg OD for 5 days
- Alt 1st line: AMOXICILLIN 500mg TDS for 5 days OR Clari 250mg - 500mg BD for 5 days, OR Erythromycin 250mg - 500mg QDS or 500mg - 1g BD for 5 days
Kids:
- 1st line: Amoxicillin
- 2nd: Clari OR Erythro OR Doxy (if 12+)
Influenza
- annual vaccination is essential for all those “at risk” of influenza
- antivirals are typically not recommended for healthy adults
- Treat “at risk” pts with OSELTAMIVIR 75mg BD for 5 days => this is primarily for when influenza is circulating in the community, and within 48h of onset (36h for zanamivir treatment in kids - only licensed for >5 YEARS.), or in a care home
- AT RISK:
=> pregnant (& up to 2-weeks post-partum)
=> <6 months
=> 65 +
=> COPD, asthma
=> CVS, NOT HTN
=> severe immunosuppression
=> renal or liver disease
=> DM
=> morbid obesity (BMI>40) - In SEVERE immunosuppression or oseltamivir resistance, use ZANAMIVIR 10mg BD (2 inhalations BD by diskhaler for up to 10 days) and seek advice
Threadworm
1st: Mebendazole for a child above 6 months, 100mg STAT (OTC: over 2 years), repeat in 2 weeks if persistent. With Mebendazole, treat with hygiene measures for 2 weeks!
TREAT ALL HOUSEHOLD CONTACTS AT SAME TIMES
If x < 6 months or pregnant, ONLY hygiene measure for 6 weeks.
TB - initial phase
Initial phase is 2 months
- rifampicin
- isoniazid
- pyrazinamide
- ethambutol
TB - continuation phase
Continuation phase is 4 months
- rifampicin
- isoniazid
TB - latent TB
3 months of rifampicin + isoniazid OR 6 months of isoniazid
Latent TB is where you’ve been infected with the TB bacteria, but do not have any symptoms of active infection.
Fungal infections - ASPERGILLOSIS
Most commonly affects the respiratory tract but in severely immunocompromised patients, invasive forms can affect the heart, brain, and skin.
Voriconazole
Fungal infections - CRYPTOCOCCOSIS
Uncommon but infection in the immunocompromised, especially in HIV-positive patients, can be life-threatening; cryptococcal meningitis is the most common form of fungal meningitis.
Amphotericin B
Fungal infections - THRUSH
- Vaginal: Clotrimazole/Fluconazole => resistant: itraconazole
- PO: 1st: Oral Miconazole gel, then 2nd: Nystatin suspension, then 3rd: fluconazole 50mg OD for 7 days if infection is severe or extensive => resistant: itraconazole
Fungal infections - SKIN AND NAIL INFECTIONS
Skin:
- 1st: topical terbinafine 1% OD to BD for 1-4 weeks OR topical imidazole 1% OD to BD for 4 - 6 weeks
Nail:
1st: Terbinafine 250mg OD for 6 weeks on fingers and 12 weeks on toes
2nd: itraconazole 200mg BD for 1 week a month (fingers = 2 course; toes = 3 courses).
Fungal infections - TINEA (ringworm)
What are the different types of ringworm called?
- Tinea capitis = head
- Tinea corporis = body
- Tinea cruris = groin
- Tinea pedis = feet
- Tinea unguium/onychomycosis = nails
Fungal infections - TINEA (ringworm)
What would you treat it with?
Nail region:
PO: Terbinafine 250mg OD for between 6 weeks and 3 months for fingernails, and 3 - 6 months for toenails.
Topical: Amorolfine 5% nail lacquer. Applied once or twice weekly. Cont. treatment for 6 months for fingernails and 9 - 12 months for toenails.
Refer to GP if under 18, more than 2 nails affected, diabetic or pregnant/breastfeeding. This isn’t licensed for children under 12. Nail polish and artificial nails should be avoided while using the treatment.
Viral infections - Varicella zoster/chicken pox/herpes zoster/shingles
1st: Aciclovir 800mg 5 times daily for chicken pox and shingles
2nd: Famciclovir 250mg - 500mg TDS OR 750mg BD for shingles if poor compliance. NOT FOR KIDS.
Chicken pox = pts 14 years and above, should take antiviral (aciclovir) 24h on onset.
Which antimalarials are used for malaria?
- Malarone (atovaquone with proguanil)
- Chloroquine - LT; okay for pregnant ppl
- Proguanil - LT; okay for pregnant ppl
- Mefloquine
- Doxycycline
Oral candidiasis
Topical azoles are more effective than topical nystatin
1st: Miconazole oral gel 2.5mL 24mg/mL QDS for 7 days and continue 7 days after resolved
2nd: Nystatin suspension 1mL (100,000units/mL) QD (half each side) for 7 days, then continue for 2 days after resolved.
3rd: Fluconazole 50mg/100mg caps OD for 7 - 14 days
Cold sores
Most resolve within 5 days without treatment!
1st: Topical antivirals such as ACICLOVIR CREAM applied early on.
If frequent/severe: give PO prophylaxis of aciclovir 400mg BD for 5 - 7 days
What is the SEPSIS 6 protocol?
- give high flow O2
- give IV abx within 1h
- give fluids - helps to increase BP
- take blood cultures to determine narrow abx treatment
- measure lactate measurements - indication of anaerobic respiration
- measure urine output - indication of kidney impairment
Acute Infective Exacerbation of COPD
3 choices used for 5 days:
- Amoxicillin 500mg TDS
- Doxycycline 200mg on day 1, then 100mg OD
- Clarithromycin 500mg BD
High risk of treatment failure:
- Co-trimoxazole 960mg BD, or co-amoxiclav 500/125mg TDS
Acute Exacerbation of Bronchiectasis (Non-Cystic Fibrosis)
3 choices used for 7 - 14 days:
- Amoxicillin 500mg TDS - preferred if pregnant
- Doxycycline 200mg on day 1, then 100mg OD
- Clarithromycin 500mg BD
High risk of treatment failure:
- Co-amoxiclav 500/125mg TDS, or Levofloxacin 500mg OD (adults ONLY), or, Ciprofloxacin 500mg OD or BD (kids ONLY)
Acute diverticulitis
1st: Co-amoxiclav 500/125mg TDS For 5 days
2nd: Cefalexin 500mg BD/TDS AND Metronidazole 400mg TDS for 5 days
OR: Trimethoprim 200mg BD AND Metronidazole 400mg TDS for 5 days
