Pharma Flashcards
Which groups of drugs cause hyperproloactinaemia?
SSRIs
Metoclopramide
Oestrogens
Opioids
H2 antagonists (Cimetidine)
Calcium channel blockers
Which progesterones are associated with high risk of VTE, when used as part of COCP?
VTE risk per 10,000 women per year
None (not pregnant) 1-2
Ethinylestradiol plus
Levonorgestrel (eg Microgynon, Rigevidon) OR
Norgestimate (eg Cilest) OR
Norethisterone (eg Loestrin, Norimin)
5-7
Ethinylestradiol plus
Gestodene (eg Femodette) OR
Desogestrel (eg Mercilon) OR
Drospirenone (eg Yasmin)
9-12
Pregnancy 10/10,000
Ethinylestradiol plus
Etonogestrel (Nuvaring) OR
Norelgestromin (Evra)
6-12
Ethinylestradiol plus
Cyproterone acetate (Dianette)
limited data approx 9-12
How do anticholinergic drugs work?
Anticholinergic drugs act by blocking muscarinic receptors in the bladder smooth muscle, leading to a direct relaxant effect.
(Bladder is M3 specifically)
Side effects: dry mouth, constipation and dry eyes occur as a result of blockade of these receptors at other sites.
Contraindications: Myasthenia gravis, significant bladder outflow obstruction, severe ulcerative colitis, toxic megacolon and in gastrointestinal obstruction or atony.
May aggravate prostatic hypertrophy and congestive cardiac failure
What are the mechanisms of action of emergency contraception?
3 types
- Levonelle (Levenogestrel)
Synthetic progesterone
1.5mg
Upto 72 hours from intercourse
EllaOne (Ullipristal)
Progesterone modulator
30mg
Upto 72 hours from intercourse
Contraindicated severe asthma or liver impairment
Copper IUD
Upto 7 days from intercourse
What is the mechanism of action of Desmopressin/DDAVP?
DDAVP is synthetic version of Vasopressin
Increases factor VIII and VWF by 3-4x
No impact of factor IX
Exerts action through V2 receptors on Endothelial cells
Uterus expresses V1 receipts - safe in pregnancy
Dose is 0.3 micrograms/kg of prepregnancy weight
Repeat doses can be given 12-24 hourly although may be less effective
Beware risk of hyponatremia - need to fluid restrict when giving
Don’t give to those on diuretics
What is the impact of anti-TNF drugs when used in pregnancy?
No difference in rate of fetal malformations
Concerns that anti-TNF accumulates in the neonate as transplacental transfer increases in later stages of pregnancy
To avoid neonatal immunosuppression it is recommended anti-TNF drugs are stopped in pregnancy as below:
All are safe with breastfeeding
Infliximab Stop at 16 weeks gestation
Etanercept Stop prior to third trimester
Adalimumab Stop prior to third trimester
Certolizumab Safe all trimesters
What is the dose of MgS04? for hypertension or neuroprotection?
A loading dose of 4 g should be given intravenously over 5 to 15 minutes, followed by an infusion of 1 g/hour maintained for 24 hours. If the woman has had an eclamptic fit, the infusion should be continued for 24 hours after the last fit.
Recurrent fits should be treated with a further dose of 2 g to 4 g given intravenously over 5 to 15 minutes
What is the MOA of Terbutaline?
Selective beta-2 adrenergic receptor agonist
What is the role of anti-D following transfusion of blood products?
Platelets - up to 5 pools 1 x 250 micrograms Anti D IM
Red blood cells: 1 unit - 1500 or 2500 IG Anti-D
More than 1 unit - Red blood cell exchange transfusion
What is the maximum dosage of lidocaine in pregnancy?
Max dose is 3mg/kg (7mg/kg with adrenaline)
Blocks fast voltage gated sodium channels
Anti-arrhythmic
Half life 2 hours
Safe to use in pregnancy
Hepatic metabolism
Which anti epileptic drugs are enzyme inducing and non enzyme inducing?
ENZYME INDUCING:
carbamazepine
phenytoin
phenobarbital
primidone
oxcarbazepine
topiramate
eslicarbazepine
Avoid COCP/Patch/ring/POP/implant for contraception
NON ENZYME INDUCING:
sodium valproate
levetiracetam
gabapentin
vigabatrin
tiagabine
pregabalin
What consideration should be taken about contraception if a woman is taking lamotrigine?
Women taking lamotrigine and oestrogen-containing contraceptives should be informed of the potential increase in seizures due to a fall in the levels of lamotrigine.
In which patients is Cabergoline contraindicated?
Cabergoline - dopamine agonist
Used to stop lactation
Contraindicated in:
Pre-eclampsia
Cardiac valvulopathy (exclude before treatment)
History of pericardial fibrotic disorders
History of puerperal psychosis
History of pulmonary fibrotic disorders
History of retroperitoneal fibrotic disorders
Hypersensitivity to ERGOT ALKALOIDS
What drugs can be used to treat uncomplicated falciparum malaria?
Treatment options for uncomplicated falciparum are:
Oral quinine 600 mg 8 hourly and oral clindamycin 450 mg 8 hourly for 7 days OR
Artemether and Lumefantrine (Riamet®) 4 tablets/dose for weight > 35 kg, twice daily for 3 days
OR
Atovaquone-proguanil (Malarone®) 4 standard tablets daily for 3 days
Describe fetal anomalies associated with antiepileptic drugs
Phenytoin:
Fetal hydantion syndrome
Includes: heart defects, cleft lip or palate, skeletal malformations, and microcephaly.
Minor malformations, including strabismus, hypertelorism, distal digital hypoplasia, nail hypoplasia, clubfoot, and abnormal dermatoglyphic patterns.
Coagulopathy occurs in ~50% of babies born to mothers on phenytoin - deficiency of vitamin K dependent clotting factors - very few of these babies are symptomatic.
Phenobarbital:
Associated with minor anomalies as with phenytoin. Exposed infants can have barbiturate depression or drug withdrawal at birth
Carbamazepine:
Associated with neural tube defects (~1% risk compared to ~0.1% background risk). Exposure to carbamazepine after the neural tube has closed (days 22-29) does not produce this defect.
Valproic acid:
RISK OF NTD FROM 6 in 10,000 to 100 to 200 in 10,000.
Associated with neural tube defects (1-2% risk) and is specific for spina-bifida, not anencephaly.
Patients with higher serum levels of valproic acid may be at greatest risk because the majority of cases occur in infants exposed to more than 1,000 mg/day.
Sodium valproate also associated with polycystic ovaries
Lithium:
Increases the rate of fetal heart defects to around 60 in 1000, compared with the risk of 8 in 1000 in the general population.
It is estimated that lithium increases the risk of Ebstein’s anomaly (a major cardiac malformation) from 1 in 20,000 to 10 in 20,000.
