Pharmacology Flashcards
Adrenaline anaphylaxis: how many ml?
0.5ml 1:1000 IM
adrenaline cardiac arrest
1mg - 10ml 1:10,000 IV or 1ml of 1:1000 IV
What receptors does adrenaline work on? (2)
acts on α 1 and 2, β 1 and 2 receptors
(causes vasoconstriction in the skin and kidneys causing a narrow pulse pressure)
amioderone:
what skin complications? (2)
Cardiac? (3)
thyroid (1)
lung (1)
liver (1)
eye (1)
Skin:
1- slate grey appearance
2- photosensitivity
Cardiac:
1- arrhythmias
2- bradycardia
3- QT lengthening
Thyoid:
1- thyroidm (hyper and hypo)
Lung
1- pulmonary fibrosis
Liver:
1- liver hepatitis
Eye:
1- corneal depositis
amiodarone interactions (2)
decreased metabolism of warfarin, therefore increased INR
increased digoxin levels
TB drug causing peripheral neuropathy
isoniazid
TB side effects
A patient has recently started treatment for TB….
1) they noticed feeling numbness in their fingertips
2) they noticed difficulty recognising colours (optic neuritis)
3) they notices their tears are orange
4) pain in their big toe (gout/ arthralgia/ myalgia)
1) I’m-so-numb-azid (Isoniazid)
2) eye-thambutol (Ethamutol)
3) red-an-orange-pissin (Rifampicin) - hepatitis, orange secretions
4) pyrazinamide
finasteride how does it work?
inhibitor of 5 alpha-reductase
used for BPH, male pattern baldness
adverse effects finasteride?
impotence
decreased libido
ejaculation disorder
gynaecomatsia
HRT: cyclical or not?
cyclical for premenopausal women as replicates normal cycles and doesn’t have breakthrough bleeding
Metformin contraindications?
- CKD: review if eGFR <45 , stop <30
- lactic acidosis if tissue hypoxia (e.g. recent MI, sepsis, AKI, severe dehydration)
- alcohol abuse
- iodine contrast
Salicylate overdose (2)
IV bicarbonate
haemodialysis
benzodiazepine overdose management
flumazenil
(only if v severe or iatrogenic due to risk of seizures)
Flumazenil can precipitate withdrawal seizures in patients with chronic benzodiazepine use and is therefore contraindicated in this patient group.
TCA overdose
IV bicarbonate
warfarin antidote if severe bleeding
Vit K + prothrombin complex
heparin antidote
protamine sulphate
BB antidote
atropine
if resistant –> glucagon
iron overdose antedote
desferriozamine (chelating agent)
lead overdose antidote
dimercaprol, calcium edetate
CO overdose management
100% O2
cyanide overdose management
Hydroxocobalamin
dehydration and lithium causes…
toxicity
normal levels = 0.4-1.0 (toxicity >1.5)
lithium toxicity management
FLUIDS
monitor serum sodium closely (every 4hr with lithium level)
haemodialysis if severe toxicity
adverse effects ahminoglycosides (gentamicin)
ototoxicity
nephrotoxicity
both peak (1 hour after administration) and trough levels (just before the next dose) are measured
if the trough (pre-dose) level is high the interval between the doses should be increased
if the peak (post-dose) level is high the dose should be decreased
viagra (sildenafil) and visual side effects
The blue pill, Viagra (sildenafil), causes blue discolouration of vision
Isoniazid (TB medication) causes peripheral neuropathy - what management
vitamin B 6 (pyridoxine)
When to give NAC in paracetamol overdose
- staggered overdose
- 8-24hr post ingestion
- > 24hr if clearly jaundiced/ hepatic tenderness/ ALT raised
criteria for liver transplant in paracetamol overdose
King’s College Hospital criteria for liver transplantation (paracetamol liver failure)
Arterial pH < 7.3, 24 hours after ingestion
or all of the following:
prothrombin time > 100 seconds
creatinine > 300 µmol/l
grade III or IV encephalopathy
causes of lung fibrosis:
amiodarone
cytotoxic agents: busulphan, bleomycin
anti-rheumatoid drugs: methotrexate, sulfasalazine
nitrofurantoin
ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)
prolonged QT interval
440ms in men and over 460ms in women
sulfalazine and lungs
lung fibrosis
disulfram - what does it do in alcohol?
promotes abstinence - alcohol intake causes severe reaction due to inhibition of acetaldehyde dehydrogenase. Patients should be aware that even small amounts of alcohol (e.g. In perfumes, foods, mouthwashes) can produce severe symptoms. Contraindications include ischaemic heart disease and psychosis
acamprosate - what does it do in alcohol?
reduces craving, known to be a weak antagonist of NMDA receptors, improves abstinence in placebo controlled trials
Which one of the following investigations is essential prior to starting anti-tuberculosis therapy?
LFTs
A 24-year-old woman presents following a sudden, acute onset of pain at the back of the ankle whilst jogging, during which she heard a cracking sound.
Ciprofloxacin may lead to tendinopathy
which antibiotics bad in pregnancy
Antibiotics
tetracyclines
aminoglycosides
sulphonamides and trimethoprim
quinolones: the BNF advises to avoid due to arthropathy in some animal studies
which drugs bad in pregnancy
Other drugs
ACE inhibitors, angiotensin II receptor antagonists
statins
warfarin
sulfonylureas
retinoids (including topical)
cytotoxic agents
The majority of antiepileptics including valproate, carbamazepine and phenytoin are known to be potentially harmful. The decision to stop such treatments however is difficult as uncontrolled epilepsy is also a risk
gliptin - important side effect on which organ
pancreatitis
glitazones side effects
weight fain, fluid retention, liver dysfunction, fractures
sulfonylureas side effects
hypoglycaemia, increased appetite, ADH syndrome, live dysfunction
what causes digoxin toxicity
classically: hypokalaemia
digoxin normally binds to the ATPase pump on the same site as potassium. Hypokalaemia → digoxin more easily bind to the ATPase pump → increased inhibitory effects
increasing age
renal failure
myocardial ischaemia
hypomagnesaemia, hypercalcaemia, hypernatraemia, acidosis
hypoalbuminaemia
hypothermia
hypothyroidism
drugs: amiodarone, quinidine, verapamil, diltiazem, spironolactone (competes for secretion in distal convoluted tubule therefore reduce excretion), ciclosporin. Also drugs which cause hypokalaemia e.g. thiazides and loop diuretics
digoxin toxicity Sx
gynaecomasia
arryhtmias
gen unwell (yellow green vision)
management digoxin toxicity
Digibind
correct arrhythmias
monitor potassium
drugs causing urinary retention
tricyclic antidepressants e.g. amitriptyline
anticholinergics e.g. antipsychotics, antihistamines
opioids
NSAIDs
disopyramide
IVDU use risk factor major
VTE
salicylate overdose (aspirin)
Both pulmonary oedema and resistant metabolic acidosis are indications for haemodialysis in salicylate overdose.
photosensitivity drugs
thiazides
tetracyclines, sulphonamides, ciprofloxacin
amiodarone
NSAIDs e.g. piroxicam
psoralens
sulphonylureas
mechanism of action of metformin
acts by activation of the AMP-activated protein kinase (AMPK)
increases insulin sensitivity
decreases hepatic gluconeogenesis
may also reduce gastrointestinal absorption of carbohydrates
Which one of the following is the most common side effect of sildenafil?
headaches
cocaine + ACS
give diazepam
QRS widening and QT prolongation
Contraindicated in breastfeeding
The following drugs can be given to mothers who are breastfeeding:
antibiotics: penicillins, cephalosporins, trimethoprim
endocrine: glucocorticoids (avoid high doses), levothyroxine*
epilepsy: sodium valproate, carbamazepine
asthma: salbutamol, theophyllines
psychiatric drugs: tricyclic antidepressants, antipsychotics**
hypertension: beta-blockers, hydralazine
anticoagulants: warfarin, heparin
digoxin
The following drugs should be avoided:
antibiotics: ciprofloxacin, tetracycline, chloramphenicol, sulphonamides
psychiatric drugs: lithium, benzodiazepines
aspirin
carbimazole
methotrexate
sulfonylureas
cytotoxic drugs
amiodarone
HTN in pregnancy AND asthmatic?
Nifedipine (not labetalol)
management of Gestational diabetes: if the fasting plasma glucose is < 7 mmol/l
if >7?
diet and exercise for 1-2 weeks
if >7 = Start insulin
if <7 and complications e.g. hydramnios, macrosomia –> start insulin
Who is screened for gestational diabetes and when?
women who’ve previously had gestational diabetes or other risk factors:
OGTT should be performed as soon as possible after booking and at 24-28 weeks if the first test is normal. NICE also recommend that early self-monitoring of blood glucose is an alternative to the OGTTs
thresholds gestational diabetes OGTT
fasting glucose is >= 5.6 mmol/L
2-hour glucose is >= 7.8 mmol/L
management of pre-existing diabetes in pregnancy
weight loss for women with BMI of > 27 kg/m^2
stop oral hypoglycaemic agents, apart from metformin, and commence insulin
folic acid 5 mg/day from pre-conception to 12 weeks gestation
detailed anomaly scan at 20 weeks including four-chamber view of the heart and outflow tracts
tight glycaemic control reduces complication rates
treat retinopathy as can worsen during pregnancy
Intrahepatic cholestasis of pregnancy increases the risk of…
stillbirth
therefore induction of labour is generally offered at 37-38 weeks gestation
breastfeeding and anti-epileptic drugs
Breast feeding is acceptable with nearly all anti-epileptic drugs
It is advised that pregnant women taking phenytoin are given vitamin K in the last month of pregnancy to prevent clotting disorders in the newborn
fetal movements: when to refer if not felt
not yet been felt by 24 weeks, referral should be made to a maternal fetal medicine unit
usually felt 18-20 weeks
RFM:
past 28 weeks what to do?
handheld doppler
–> if no HR –> US
–> if HR –> CTG for 20 mins to monitor
causes of folic acid deficiency? (4)
who gets 5mg folic acid? (6)
phenytoin
methotrexate
pregnancy
alcohol excess
previous pregnancy with NTD or FH NTD
antiepileptic drugs
coeliac disease
diabetes
thalassaemia
obese (>30)
folic acid for women - how much and until when? (2)
400mcg until 12th week pregnancy
Pregnancy >20 and chickenpox rash
oral acyclovir
chickenpox exposure in pregnancy?
if unsure if prev infection –> Check maternal varicella antibodies
if not –> give varicella zoster immunoglobulin
if infected –> give acyclovir
antivirals should be given at day 7 to day 14 after exposure, not immediately
aspirin and breastfeeding
contraindicated
Magnesium sulphate: what to monitor whilst giving for pre-eclampsia
monitor reflexes + respiratory rate
urine output, reflexes, respiratory rate and oxygen saturations should be monitored during treatment
- respiratory depression can occur: calcium gluconate is the first-line treatment for magnesium sulphate induced respiratory depression
treatment should continue for 24 hours after last seizure or delivery (around 40% of seizures occur post-partum)
breastfeeding: Candia infection treatment
Miconazole for mother: applied after each feed
Nystatin for oral mucosa of baby
Mastitis management:
when to treat? (3)
treatment (1)
‘if systemically unwell,
if nipple fissure present
if symptoms do not improve after 12-24 hours of effective milk removal of if culture indicates infection
flucloxacillin for 10-14 days
moderate (x2 factors)/ of 1x high risk of pre eclampsia: what medication should they have? (1)
A woman at moderate or high risk of pre-eclampsia should take aspirin 75-150mg daily from 12 weeks gestation until the birth
Pre-eclampsia: definition
new-onset blood pressure ≥ 140/90 mmHg after 20 weeks of pregnancy, AND 1 or more of the following:
proteinuria
other organ involvement (see list below for examples): e.g. renal insufficiency (creatinine ≥ 90 umol/L), liver, neurological, haematological, uteroplacental dysfunction
High risk factors preeclampsia (5)
hypertensive disease in a previous pregnancy
chronic kidney disease
autoimmune disease, such as systemic lupus erythematosus or antiphospholipid syndrome
type 1 or type 2 diabetes
chronic hypertension
Moderate risk factors pre-eclampsia:
first pregnancy
age 40 years or older
pregnancy interval of more than 10 years
body mass index (BMI) of 35 kg/m² or more at first visit
family history of pre-eclampsia
multiple pregnancy
if 2x of these then get aspirin
BP >160/110 in pregnancy
admit and observe
SSRIs of choice in breastfeeding women
sertraline and paroxetine
GBS screening - yes/no?
doesn’t exist
GBS:
who to give prophylaxis?
- if GBS in previous pregnancy
- if women are to have swabs for GBS this should be offered at 35-37 weeks or 3-5 weeks prior to the anticipated delivery date
IAP should be offered to women with a previous baby with early- or late-onset GBS disease
IAP should be offered to women in preterm labour regardless of their GBS status
women with a pyrexia during labour (>38ºC) should also be given IAP
benzylpenicillin is the antibiotic of choice for GBS prophylaxis
Perineal tear:
1st –> 4th what are they? (4)
where to repair (4)
1st - superficial damage with no require any repair
2nd - injury perineal muscle but not anal spincter = suture on the ward
3rd - injury to perineum involving anal spincter complex (EAS AND/or IAS) = repair in theatre
4th - AND rectal mucosa
= theatre
When is anomaly scan done?
18-20 +6 weeks
Dating scan date?
8 weeks
Nuchal scan?
11 weeks
methotrexate: when to stop in pregnancy?
at least 6 months before conception in both men and women
NSAIDS and pregnancy
NSAIDs may be used until 32 weeks but after this time should be withdrawn due to the risk of early close of the ductus arteriosus
Umbilical cord prolapse
ARound 50% of cord prolapse occurs after artificial rupture of membranes
UTI + breastfeeding: what management?
trimethoprim
Abruption:
associated factors? (5)
proteinic HTN
cocaine
multiparity
trauma
increasing maternal age
Active third stage:
steps (3)
uterotonic drugs
clamping of cord between 1 and 5 mins
controlled traction of cord
(10 IU oxytocin by IM injection - given after delivery anterior shoulder)
Risk of gestational diabetes: when to do OGTT?
Women who are at risk of gestational diabetes should have an oral glucose tolerance test as soon as possible after booking, rather than waiting to 16-18 weeks as was previously advocated.
2 supplements for pregnant women
folic acid and vitamin D
Rhesus -ve
when to give anti-D? (2)
what to do if bleeding? (1)
what situations to give Anti-D immunoglobulin? (8)
Anti-D 28 and 34 weeks
if event is in 2nd/3rd trimester give large dose of anti-D and perform Kleihauer test - determines proportion of fetal RBCs present
delivery of a Rh +ve infant, whether live or stillborn
any termination of pregnancy
miscarriage if gestation is > 12 weeks
ectopic pregnancy (if managed surgically, if managed medically with methotrexate anti-D is not required)
external cephalic version
antepartum haemorrhage
amniocentesis, chorionic villus sampling, fetal blood sampling
abdominal trauma
sensorineural deafness
congenital cataracts
congenital heart disease (e.g. patent ductus arteriosus)
growth retardation
hepatosplenomegaly
purpuric skin lesions
‘salt and pepper’ chorioretinitis
microphthalmia
cerebral palsy
congenital rubella
MMR vaccine and pregnancy - when to give?
AFTER pregnancy NOT during!
Cut offs iron therapy in pregnancy
1st= <110
2nd/3rd= <105
postpartum= <100
Physiological changes in pregnancy
In pregnancy there are a number of physiological changes that take place and many of these are normal. Ventilation rates are known to increase in pregnancy due to the increased demand for oxygen and the increased basal metabolic rate. Oxygen consumption can increase by as much as 20%.
For the cardiovascular system. Plasma volume increases which results in an increase heart rate, stroke volume and cardiac output. From a haematological point of view the plasma volume increased by up to 50% and the red blood cell volume increase by about 20-30%. Due to this discrepancy, the haematocrit can decrease due to the dilution effect.
Oligohydraminos:
causes (5)
premature rupture of membranes
Potter sequence
bilateral renal agenesis + pulmonary hypoplasia
intrauterine growth restriction
post-term gestation
pre-eclampsia
rudimentary digits, limb hypoplasia and microcephaly
chicken pox
pregnancy and smoking risks
miscarrigage
preterm labour
stillbirth
IUGR
increased sudden unexpected death in infancy
alcohol and pregnancy:
Fetal alcohol syndrome:
learning difficulties
characteristic facies: smooth philtrum, thin vermilion, small palpebral fissures, epicanthic folds, microcephaly
IUGR & postnatal restricted growth
Stage 2 labour:
what is it? (1)
from full dilation to delivery of foetus
Stage 2 labour:
how long last?
1 hr approx
if >1 hr consider ventouse, forceps, or CS
A/W transitent bradycardia
Delivery is possible in the OP position, however labour is likely to be longer and more painful. (occipital posterior)
may spontaneously rotate
oligohydraminos definition
<500ml
Early scan
10 - 13+6 weeks
ECV: when done?
36 weeks if breech
from 3 weeks if multiparous
Sudden collapse post rupture of membranes
amniotic fluid embolism
Clinical diagnosis of exclusion, as there are not definitive diagnostic tests.
twins + increased size of abdomen and/or SOB
twin-to-twin transfusion syndrome
in MONOChorionic twins
Puerperal pyrexia:
deinfition (1)
most common cause (1)
other causes (4)
management (1)
temperature of > 38ºC in the first 14 days following delivery.
endometriitis
others:
UTI
mastitis
wound infection
VTE
–> HOSPITAL for IV ABC
HIV and pregnancy:
how to reduce transmission to infant?
maternal antiretroviral therapy
mode of delivery (caesarean section)
neonatal antiretroviral therapy
infant feeding (bottle feeding)
Pre-eclampsia:
when to give brith?
pregnant women who have mild or moderate gestational hypertension, are more than 37 week pregnant, and are showing signs of pre-eclampsia, should be recommended to give birth within 24 - 48 hours.
What is Bishop score? (1)
help assess whether induction of labour will be required
a score of < 5 indicates that labour is unlikely to start without induction
a score of ≥ 8 indicates that the cervix is ripe, or ‘favourable’ - there is a high chance of spontaneous labour, or response to interventions made to induce labour
Bisop score <6?
Bishop score >6?
if the Bishop score is ≤ 6
vaginal prostaglandins or oral misoprostol
mechanical methods such as a balloon catheter can be considered if the woman is at higher risk of hyperstimulation or has had a previous caesarean
if the Bishop score is > 6
amniotomy and an intravenous oxytocin infusion
PROM: management
oral erythromycin for 10/7
antenatal corticosteroids should be administered to reduce the risk of respiratory distress syndrome
Downs syndrome:
when are tests done? (1)
What happens to HCG, PAPP-A and ducal translucent? (3)
what if women miss testing? (1)
11-13+6 weeks
↑ HCG, ↓ PAPP-A, thickened nuchal translucency
trisomy 18 (Edward syndrome) and 13 (Patau syndrome) give similar results but the hCG tends to lower
if women book later in pregnancy the quadruple test should be offered between 15 - 20 weeks
quadruple test: alpha-fetoprotein, unconjugated oestriol, human chorionic gonadotrophin and inhibin A
higher chance of Downs syndrome at 11-13+6 week scan. What to do?
Women who have a ‘higher chance’ combined or quadruple tests result are offered either further screening (NIPT) or diagnostic tests (amniocentesis, CVS)
NIPT= more sensitive+specific –> higher chance
Which UTI Abx to avoid in CKD3?
nitrofurantoin (and tetracycline)
Drugs to avoid renal failure
antibiotics: tetracycline, nitrofurantoin
NSAIDs
lithium
metformin
diuretics
Drugs likely to accumulate in chronic kidney disease - need dose adjustment
most antibiotics including penicillins, cephalosporins, vancomycin, gentamicin, streptomycin
digoxin, atenolol
methotrexate
sulphonylureas
furosemide
opioids
when to avoid nitrofurantoin in pregnancy?
LAST semester (risk of haemolysis in the neonate)
Allopurinol (gout) and azathioprine (IBD) together..
neutropenic sepsis
Alloporinol:
how does it work?
inhibiting xanthine oxidase.
Digoxin:
what monitoring is required? (1)
what is it used for? (2)
how is it monioted? (1)
none (except in suspected toxicity)
AF rate control
SYMPTOMS of HF but not mortality
if toxicity suspected measure conc within 8-12hr of last dose
Digoxin toxicity features
generally unwell, lethargy, nausea & vomiting, anorexia, confusion, yellow-green vision
arrhythmias (e.g. AV block, bradycardia)
gynaecomastia
determined by symptoms not plasma concentration
Main cause of digoxin toxicitiy
hypokalaemia
diclofenac and cardiovascular disease
CONTRAINDICATED
kings college hospital criteria
for paracetamol overdose needing liver transplant
Arterial pH < 7.3, 24 hours after ingestion
or all of the following:
prothrombin time > 100 seconds
creatinine > 300 µmol/l
grade III or IV encephalopathy
Quinolones (ciprofloxacin and levofloxacin)
adverse effects
tendon rupture
seizures
QT
avoid in pregnancy
tamoxifen side ffects
menstrual disturbance: vaginal bleeding, amenorrhoea
hot flushes - 3% of patients stop taking tamoxifen due to climacteric side-effects
venous thromboembolism
endometrial cancer
(acts like oeastrogen)
vision changes to drugs:
blue (1)
green-yellow (1)
blue vision: Viagra (‘the blue pill’)
yellow-green vision: digoxin
what causes lithium toxicity
dehydration
renal failure
drugs: diuretics (especially thiazides), ACE inhibitors/angiotensin II receptor blockers, NSAIDs and metronidazole.
Herceptin (trastuzumab) adverse effects
Adverse effects
flu-like symptoms and diarrhoea are common
cardiotoxicity
more common when anthracyclines have also been used
an echo is usually performed before starting treatment
allopurinol, and azathioprine
Allopurinol increases risk of azathioprine toxicity
(NEUROPENIC SEPSIS due to azathioprine)
digoxin drug monitoring
NONE routinely
monitoring of heparin
LMWH= NONE
unfractionate heparin= APTT measurement
adverse effects heparin
bleeding
thrombocytopenia - see below
osteoporosis and an increased risk of fractures
hyperkalaemia - this is thought to be caused by inhibition of aldosterone secretion
lithium In pregnacy
cardiac abnormalities= Abstains anomaly
chloramphenicol in pregnacy: what does it cause?
grey baby syndrome
urinary retention
tricyclic antidepressants e.g. amitriptyline
anticholinergics e.g. antipsychotics, antihistamines
opioids
NSAIDs
disopyramide
most common SE of tamoxifen
hot flushes - 3%
(also VTE or endomeitral cancer and menstrual disturbance but less common)
What complications are most commonly associated with gentamicin?
(aminoglycaside) (2)
nephrotoxic AND ototoxic
Toxicity may be precipitated by which factors (2)
which drugs? (4)
dehydration
renal failure
drugs:
diuretics
ACEi/ ARBs
NSAID
metronidazole
features lithium toxicity
coarse tremor (a fine tremor is seen in therapeutic levels)
hyperreflexia
acute confusion
polyuria
seizure
coma
drug induced thrombocytopenia
quinine
abciximab
NSAIDs
diuretics: furosemide
antibiotics: penicillins, sulphonamides, rifampicin
anticonvulsants: carbamazepine, valproate
heparin
cocaine toxicity: metabolic acidosis or alkalosis?
The correct answer is Metabolic alkalosis. Cocaine toxicity does not typically lead to metabolic alkalosis. Instead, it often results in metabolic acidosis due to increased lactate production from tissue ischemia and rhabdomyolysis. This occurs as a result of cocaine’s sympathomimetic effects which increase the body’s demand for oxygen, leading to tissue hypoxia.
metformin and ACS
STOP metformin in MI as –> lactic acidosis
Aspirin overdose within 1hr
charcoal
Azathioprine monitoring
FBC LFT
if CCB not tolerated in step 1 for people of black African/ Carribean heritage then
thiazide like diuretic
amoebic liver disease treament
metronidazole
Diabetes drug adverse effects
lower limb amputation
bladder cancer
vit B12 def
SGLT2 inhibitor= lower limb amputaiton (FLOZIN)
bladder cancer= pioglitazone
Meformin= B12
DMARD with serious ocular toxicity problems
Hydroxychloroquine
When is CLOPIDOGREL rather than aspirin used in prevention of cardiovascular disease
ASPIRIN=
post MI
CLOPIDOGREL=
PAD
stroke
TIA
Benzylpenicillin vs phenoxymethylpenicillin
shorted= for meningococcal disease
LONGER= THROAT infection
ALT and AST in the 10,000? most likely cause
paracetamol overdose
doxazocin- what type of drug
alpha blocer
used 1st line BPH
drugs which cause digoxin toxicity
drugs: amiodarone, quinidine, verapamil, diltiazem, spironolactone (competes for secretion in distal convoluted tubule therefore reduce excretion), ciclosporin. Also drugs which cause hypokalaemia e.g. thiazides and loop diuretics
CYP450 and TB medications
RifAMPicin = AMPs up CYP450
Isoniazid = Inhibits
skin change with doxycycline
photosensitivity
which Abx do you get reaction with alcohol
metronidazole (