Pharmacology Flashcards
Yellow staining of baby’s teeth due to mother taking which drug during pregnancy
Lymecycline (Tetracyclins)
Which antibiotic is associated with the risk of neonatal hemolysis
Nitrofurantoin (treating UTI)
Co-trimoxazole (treating upper respiratory infections)
Baby has a defect of the 8th cranial nerve, which medication did his mother take during pregnancy
Streptomycin (aminoglycosides)
Mode of Action of Atosipan (tocolytic)
Oxytocin receptor antagonist
according to nice guidelines, what is the 1st line tocolytic
Nefidipine (ca channel blocker)
Only indications to give b2 agonist as a tocolytic
External cephalic version: Terbutaline SC
Emergency tocolyisis (in case of oxytocin hyper-stimulation): Terbutaline IV
Most used uterotonic
Oxytocin
Oxytocin side effects
• Tachycardia/Arrhythmia
• HTN
• Oliguria
• Natriuretic/Hyponatremi
Forms of prostaglandin used as uterotonic
○ Misoprostol(Most commonly used).
○ Dinoprostone
○ Dinoprost
○ Carboprost
All prostaglandins are derived from
arachidonic acid
Uses of mifepristone as a uterotonic
• Emergency contraception.
• Medical termination of pregnancy (IUFD – Abortion) #
Mifepristone mode of action
Competitive progesterone receptor antagonist
“Selective progesterone receptor modulator (SPRM)”
Side effects of Ergometrin
Ergotism (st anthony’s fire)
Diarrhea
Vomiting.
can cause sever vasoconstriction
Misoprostol is of what type of prostaglandin
Synthetic Prostaglandin E1 analogue (most commonly used)
Dinoprostone is of what type of prostaglandin
Naturally occurring Prostaglandin E2
Dinoprost is of what type of prostaglandin
Naturally occurring Prostaglandin F2 Alpha.
Carboprost is of what type of prostaglandin
Synthetic Prostaglandin F2 Alpha analogue
Half life of Misoprostol
40 minutes
1st choice uterotonic in preventing PPH
Oxytocin
Half life of Oxytocin
5 minutes
Oxytocin Side effects
• Tachycardia/Arrhythmia
• HTN
• Oliguria
• Natriuretic/Hyponatremia
The half-life of ergometrine
approximately 30-120 minutes
Uteritonic Drugs used in the third stage of labour
- Syntometrine® (Ergometrine 500mcg / Syntocinon 5IU) IM.
- Syntocinon
- Misoprostol 800mcg (PGE1 analogue)
- Carboprost® (PGF2α analogue)
Syntometrine is contraindicated in
hypertensive pregnancies.
Side effects of misoprostol
commonly diarrhoea and nausea/vomiting
Misoprostol method of administration
Taken orally / vaginally / rectally
Carboprost method of administration
IM or intra-myometrial
Carboprost cautions
Caution required in hypertension
Avoided in asthmatics.
the preferred method of induction of labour
vaginal PGE2
unless there are specific clinical reasons for not using it (in particular the risk of uterine hyperstimulation)
Misoprostol & Mifepristone should only be offered as a method of induction of labour in a women with?
Intrauterine fetal death
Why we don’t give oral oxytocin?
As it is destroyed by gastric acid
Peripheral function of Oxytocin
- letdown reflex
- Uterine contractions
From where prostaglandin is produced by
all nucleated cells except for lymphocytes
Prostaglandin is used in obstetrics in
- Induction of labour
- Termination of pregnancy
- Management of PPH
Common side effects of Dinprostone PGE2
Diarrhea
Transient Pyrexia
What is Ergotism?
Side effect of Ergometrine
prolonged vasospasm results in gangrene, hallucination, abortion)
In induction of labour, Membrane sweeping is indicated for nulliparous women at
40 to 41 weeks of gestation
In induction of labour, Membrane sweeping is indicated for parous women at
41 weeks of gestation
Mifepristone isn’t offered in which types of abortions
missed and incomplete miscarriage
(we use vaginal misopristol)
Medical management of missed miscarriage
single dose 800 micrograms of vaginal misoprostol
Medical management of incomplete miscarriage
single dose of 600 micrograms of misoprostol.
(800 micrograms can be used as an alternative to allow alignment of treatment protocols for both missed and incomplete miscarriage.)
We offer all women receiving medical management of miscarriage ?
pain relief and anti-emetics as needed.
Rhesus Anti-D IgG (if needed)
We offer antibiotic prophylaxis to medical or surgical abortion
Only surgical
(oral doxycycline 100 mg twice a day for 3 days)
In managing PPH, we offer how many RBC units
4 units of red blood cells
In managing PPH, What is the ration of RBC to FFP offered
RBC:FFP
6:4
In managing PPH, When we start FFP administration
after 4 units of RBCs
First line surgical intervention in managing PPH
Intrauterine balloon tamponade
What are Uterotonics contraindicated in HTN
- Oxytocin
- Ergometrine
3.Syntometrine - Carboprost
What are Uterotonics tolerable in HTN
- Syntocinon (infusion of 40IU in saline)
2.Misoprostol (orally - vaginally - rectally)
Mechanism of action of Terbutaline
B2 agonist
mifepristone mode of action
Progesterone antagonist
Half life of Mifepristone?
25-30 hrs
Types of Tocolytics
- Atosiban (Oxytocin receptor antagonist)
- B2 agonists (salbutamol- terbutaline- ritodrine
- Ca channel Blockers (nifedipine)
- MGSO4
- GTN Patches
Route of administration of Atosiban
IV
Side effects of Nifedipine
VD, Hypotension and tachycardia
Side effects of B2 agonist
• Tachycardia
• Hypotension
• Pulmonary oedema
• Hypokalaemia
• Hyperglycaemia
Guidelines in Tocolysis in Preterm Labour
○ Intact membrane, Suspected PTL, 24w to 25+6 = consider Nifedipine
○ Intact membrane, Suspected PTL, 26w to 33+6 = offer Nifedipine
○ If nifedipine is CI, offer oxytocin receptor antagonists for tocolysis.
○ Do not offer beta-mimetics for tocolysis
the major mood stabilizer in the UK for over 40 years
lithium carbonate
therapeutic window of lithium carbonate
The therapeutic range of plasma concentration is narrow: 1–1.5 mEq/l.
Below 1 mEq/l there is no psychotropic effect
Above 1.5 mEq/l toxic effects begin to develop.
Two of the most important actions of lithium are
- inhibition of cyclic AMP production
- reduction in receptor-stimulated phosphatidylinositol turnover.
Most serious in using Lithium during pregnancy
Epstein anomaly in the fetus
Which anti-epileptic drug carries the greatest risk of neural tube defects
Sodium valproate
Midazolam is an effective anxiolytic drug, used for preoperative sedation. Which receptor is responsible for its action
GABA
Paroxetine is teratogenic to which organ ?
CVS
Diazepam can cross placenta, due to?
Lipid solubility
Use of which agents during pregnancy is associated with “floppy
infant syndrome?
Diazepam
First line Antihypertensive drug in pregnancy
Labetalol (labipress)
Labetalol mode of action
Selective alpha and non-selective beta antagonist
It exerts its antihypertensive effect mainly through blockade of the β 1 -receptors expressed in the heart.
Labetalol Side-effects
• Atrioventricular block and congestive cardiac failure
•IUGR with prolonged use.
• Neonatal hypoglycaemia + bradycardia have rarely been reported.
• avoided in asthmatics, leads to bronchospasm
diabetics leads to hypoglycemia
in people with peripheral vascular disease as it leads to ischemic limb.
Methyldopa mode of action
Centrally acting α2 –adrenoceptor agonists
Role of Methyldopa as an antihypertensive drug in pregnancy
considered as second line treatment as an add on to labetolol but may be used first line instead
Major side effect of Methyldopa that puts Labetalol in advantage
Postpartum depression (with long term use)
Mode of action of Hydralazine as antihypertensive
direct acting vasodilator
Mode of administration of Hydralazine
It needs to be given slowly over a minimum of 5 minutes IV.
It can be repeated IV every 15 minutes if needed
It’s proven to be the best prevention and best treatment of fits in severe PET / Eclampsia.
MgSO4
While treating with MgSO4, when it’s required to monitor MgSO4 level?
If the patient is oliguric
MgSO4 toxicity signs
• Hyporeflexia presents in advance of more serious effects
• Respiratory depression
• Cardio-respiratory arrest
Monitoring of MgSO4 therapy
• Clinical (Hourly tendon reflexes)
• Renal function (Hourly urine output)
• Cardio-respiratory (ECG during and for 1 hour after loading dose – O2 saturation continuously)
Anti-HTN drugs to be avoided in pregnancy
- ACEI
- Thiazaide diuretics
- Statins
Which anti-epileptic drug carries the greatest risk of neural tube defects?
Sodium Valproate
Use of which agent during pregnancy is associated with “floppy infant syndrome”?
Diazepam
Diazepam can cross placenta, due to?
Lipid solubility
Pregnant women with epilepsy have the highest risk of breakthrough seizures during?
Postpartum
All babies born to WWE taking enzyme-inducing AEDs should be offered
1 mg of intramuscular vitamin K to prevent hemorrhagic disease of the newborn.
Main Cause of Death in WWE (women with epilepsy)
SUDEP - Sudden unexpected death of epilepsy
the strongest risk factor for SUDEP
uncontrolled tonic-clonic seizures
Enzyme Inducing AEDs
Carbamazepine,
Phenytoin,
Phenobarbital,
Topiramate,
Primidone,
Oxcarbazepine &
Eslicarbazepine
Non-enzyme Inducing AEDs
Sodium Valproate,
Levetiracetam,
Gabapentin,
Vigabatrin,
Tiagabine
&Pregabalin
Anti-epileptic Drugs are associated with increased teratogenicity like
✓ NTDS
✓ Cleft lip and palate
✓ Cardiac defects
✓ Urogenital defects
✓ Neonatal coagulopathies
✓ Skeletal abnormalitie
Malformations associated with Phenytoin
Phenytoin is associated with malformations mainly due to alterations in folate metabolism.
The fetal anticonvulsant syndrome is:
✓ Cleft lip/palate
✓ Microcephaly
✓ Cardiac abnormalities
✓ Mental retardation
• Not associated with NTDS
Mode of action of Diazepam
Positive modulator of GABA
Antidote of Diazepam
Flumazenil
Diazepam can causes
Neonatal benzodiazepine withdrawal syndrome (floppy infant syndrome) when taken in 3rd trimester.
What AEDs has the least risk of fetal malformations
lamotrigine, and carbamazepine monotherapy at lower doses
According to RCOG guidance antenatal steroids should be offered to which group undergoing elective C-section?
C-section prior to 38+6 weeks gestation
Which antiemetic drug can cause uncontrolled muscle movements?
Metoclopramide
(2nd line ttt after promethazine)
Is labetalol associated with orthostatic hypotension
NO
What drug can be given to reverse myelosuppression (bone marrow suppression) in methotrexate toxicity?
Folonic Acid
Which cytokines are secreted by virally infected host cells and Stimulates
uninfected neighbouring cells to synthesize antiviral proteins?
Interferons alpha and beta (IFN α and IFN β)
Acyclovir mode of action
guanine analogue, Inhibits viral DNA polymerase.
Is Ribavirin indicated in pregnancy
FDA pregnancy category X.
Clinically used interferons
(INF-α) are used in treatment of chronic HBV and HCV infections and
also in refractory condyloma acuminate (genital warts).
What is Protein C
Physiological anticoagulant
Activated by thrombin
Degrades factors Va and VIIIa
What is Protein S
Co-factor with protein C
What is Factor V Leiden
Variant of factor V that cannot be inactivated by protein C
Causes hyper-coagulant state
Autosomal dominant condition
Present in 30% of patients with DVT and PE
Heparin mechanism of action
Activates anti-thrombin III causing inactivation of Thrombin (factor IIa) and factors IXa, Xa, XIa, and XII.
Heparin Route of administration
○ Heparin is administered intravenously or subcutaneously
○ It has a half life of about 1 hour.
○ Usually it is given by infusion after a bolus loading.
○ It is monitored by APTT.
Antidote of Heparin
Protamine sulphate.
Is heparin safe in pregnancy
Yes, it doesn’t cross placenta. It also isn’t secreted in milk
Heparin Side effects
- Haemorrhage (Treated by ceasing administration and, if necessary, administration of protamine)
- Heparin-induced thrombocytopenia (Due to the development of antibodies after 4–5 days
administration). - Osteoporosis.
- Alopecia.
- Hyperkalemia.
Is warfarin safe in pregnancy
No, it crosses the placenta.
may cause warfarin embryopathy in 5% of fetuses exposed in 6-12 weeks
Is warfarin safe in breast feeding
yes
What should women on warfarin do during pregnancy
Convert to LMWH, unless the thrombo-embolic risk is so high that it needs to be continued e.g. metallic heart valves”.
Convert back to warfarin 5-7 days after delivery
Can we use warfarin anytime in pregnancy.
May be used between 12 – 36 weeks if absolutely necessary, but as they cross the placenta they cause anti-coagulation in the fetus and as such there is a risk of fetal intracranial haemorrhage, especially if taken close to delivery.
Warfarin mode of action
inhibiting vitamin K dependent clotting factors (10,9,7,2)
Warfarin antidote
FFP, Vitamin K and Prothrombin complex concentrate.
Warfarin embryopathy
It is associated with multiple cranio-facial and skeletal abnormalities (Conradi-Hunnerman syndrome)
○ Hypoplasia of nasal bridge
○ Congenital heart defects
○ Ventriculomegaly
○ Agenesis of the corpus callosum
○ Stippled epiphyses
When should the last therapeutic dose of low molecular weight heparin (LMWH) be stopped before regional anaesthesia?
24 hrs
What is Tissue plasminogen activator (t-PA)
• Catalyzes conversion of plasminogen to plasmin which is a fibrinolytic enzyme.
• Examples: Alteplase and Reteplase.
• Antidote: Aminocaproic acid (anti-fibrinolytic)
What is the mechanism of action of Dabigatran?
Thrombin inhibitor
When should the prophylactic dose of low molecular weight heparin (LMWH) be stopped before regional analgesia?
12 hrs
Coumarin drug antagonize which vitamin?
Vit K
Thromboprophylaxis on patient with hyperemesis ?
Until discharge (disease dissolve)
recommended drug of choice for prophylaxis of malaria in pregnancy
Mefloquine (5mg/kg once a week) is the recommended drug of choice for prophylaxis in the second and third trimesters for chloroquine-resistant areas.
Severe or complicated malaria TTT
Artesunate I.V.
Or
Quinine I.V + Clindamycin I.V.
Quinine is associated with severe and recurrent hypoglycaemia in late pregnancy.
Uncomplicated malaria TTT
P. Falciparum - Resistant P. Vivax:
Quinine (oral) + Clindamycin (oral)
Or
Riamet
Or
Malarone
Non P. Falciparum (P. Vivax – P. Ovale – P. Malariae):
Chloroquine (oral)
What is the mechanism of action of trimethoprim?
Inhibits dihydrofolate reductase
(Anitbiotic)
Heparin structure
sulphate polysaccharide
Which of the following Antineoplastic drugs causing hemorrhagic cystitis?
Cyclophosphamide
Mechanism of action of ulipristal acetate
selective progesterone receptor modulator
used in emergency contraception and fibroids
Botulinum toxin is now used to treat neurogenic bladder because of its ability t
Inhibit the release of acetylcholine
Male came for infertility check up who was taking Finasteride for treatment of his
male pattern baldness. Finasteride exert its action by inhibition of which enzyme?
5-alpha reductase
What is the mechanism of Letrozole drug ?
Aromatase inhibitor
Drosperinone is?
Progestogen
What is the mode of action of Tranexamic acid?
What is the mode of action of Tranexamic acid?
Inhibits Plasminogen Activation
Which is non-ergot dopamine agonist drug used to treat hyperprolactinemia?
Quinagolide
How much Mirena secretes in 24 hours ?
20 micro grams
What is the most common side effect with etonogestrel implant?
Infrequent bleeding
Why ramifentanil used in patient controlled analgesia?
Short acting easily metabolized by serum esterase
The generation of prostanoids is catalysed by the enzyme
prostaglandin H2 synthase, also known as cyclooxygenase (COX)
NSAIDs mode of action
lock the first oxidation step of arachidonic acid (precursor of all eicosanoids) that is catalysed by COX enzyme.
With regard to opioid receptors. Fentanyl acts primarily as a potent?
Mu receptor agonist
- morphine
- methadone
Types of Progesteron only pills
- Traditional (e.g. Femulen®, Micronor®, Norgeston®): thickening cervical mucus so preventing sperm entry at neck of womb.
- Desogestrel (e.g. Cerazette®):have potential benefits over traditional POPs because ovulation is inhibited in up to 97% of cycles and they have a 12-hour window for missed pills.
Benefits of using Desogestrel POPs
have potential benefits over traditional POPs because ovulation is inhibited in up to 97% of cycles and they have a 12-hour window for missed pills. It also thicken cervical mucus.
Side effects of POPs
○ Changes in bleeding patterns (Irregular bleeding)
○ Mood changes (Depression)
○ Acne
○ Breast discomfort
○ While the overall risk of pregnancy is reduced with use of traditional POPs, around 1 in 10 pregnancies that do occur may be ectopic
If a woman vomits within 2 hours of POPs taking?
- If a woman vomits within 2 hours of pill taking, another pill should be taken as soon as possible.
- If the subsequent pill is missed, additional precautions are required until 48 hours after pill taking has been resumed.
Window for missed pills in Desogestrel?
12 hours window
Window for missed pills in traditional POPs?
3 hours window
POPs missed pills protocol
-the pill should be taken once the patient remembered it.
- if 2 pills are missed, only one pill should be taken.
- the next pill should be taken at the usual time, that may mean that 2 pills may be taken in one day.
- Additional contraceptive precautions shall be used for 48 hours after resuming the POPs.
-Emergency contraception is indicated if unprotected sexual intercourse happened within this 48 hours.
Types of Combined hormonal contraceptives in UK
○ Combined oral contraceptive pill (COC)
○ Combined transdermal patch (CTP) that releases an average of 33.9 μg EE and 203 μg norelgestromin per 24 hours.
○ Combined vaginal ring (CVR) that releases EE and etonogestrel at daily rates of 15 μg and 120 μg, respectively.
Constituents of Combined transdermal patch (CTP)
Combined transdermal patch (CTP) releases an average of 33.9 μg ethinyloestradiol and 203 μg norelgestromin per 24 hours.
Constituents of Combined vaginal ring (CVR)
Combined vaginal ring (CVR) releases Ethinyloestradiol and etonogestrel at daily rates of 15 μg and 120 μg, respectively.
What is Co-cyprinidiol?
Co-cyprindiol (containing 35 μg EE with cyproterone acetate, an anti-androgen) is indicated for management of
moderate to severe acne and hirsutism. Women using co-cyprindiol for these indications do not require additional
contraception.
Emergency contraception
- Ulipristal (EllaOne®) :Effective up to 5 days after sexual intercourse.
- Copper IUD: Can be inserted up to 120 hours after SI.
- Levonogestrel: up to 72 hours after SI
Ulipristal is thought to prevent pregnancy by what primary mechanism?
Inhibition of ovulation
Which of the following best describes Ulipristal?
Selective Progesterone Receptor Modulator
What is the most common adverse effect experienced by women taking the progestogen only pill?
Irregular bleeding pattern
FINASTERIDE EXERT ITS ACTION BY INHIBITION OF WHICH ENZYME?
5-ALPHA REDUCTASE
Following Ectopic pregnancy, What percentage of women treated mediccaly with methotrexate single dose will require surgical intervention?
7% will require surgical intervention
15% will require another dose
- What is the most common adverse effect experienced by women taking the progestogen-only pills
Erratic bleeding
What is the most common side effect with etonogestrel implant
Infrequent bleeding
Mirena secret in 24 hours ?
20 mcg initially.
18mcg 1 year after insirtion.
12 mcg 4 years after insertion
10mcg 5 years after insertion
Mechanism of action of Apixaban
Direct inhibitor of factor Xa
Fluconazole mechanism of action
Potent inhibitor of ergosterol synthesis
Diethylstilbestrol associated with which neoplasm
Clear cell adenocarcinoma
What is diethystilbesterol
Synthetic estrogen
Mechanism of action of indomethacin
Cyclo-oxygenase inhibitor
What normal physiological changes seen in pregnancy are associated with a slower drug metabolism
Delayed gastric emptying
Mechanism of action of Neostigmine is?
Anticholinesterase
INH (isoniazid) Metabolism is by ?
Acetylation
For women with GBS who have agreed to IAP what drug should be used
- Benzylpenicillin (till delivery)
- cephalosporin (if not severely allergic to penicillin)
- vancomycin ( if severely allergic to penicillin)
- Clindamycin (no longer used as it’s 16% resistant)
First line outpatient therapy of PID
IM ceftriaxone 1g single dose +
Oral doxycycline 100mg BD for 14 days +
Oral metronidazole 400mg BD for 14 days
S/E of chemotherapy
- Bone Marrow suppression (neutropenia-anemia-thrombocytopenia)
- Nausea and Vomiting
- Mucositis (esp. methotrexate)
- Alopecia (esp. Taxanes)
Pregnancy related nausea and vomiting uses PUQE index. What is the Maximum
score?
15
Pregnant women with Nausea and vomiting. Which fluid should no be given?
5% Dextrose
Clavulanic acid is what type of drug
Beta lactamase inhibitor
What is the maximum dose of lidocaine the should be used in a pregnant woman
21ml 1% lidocaine
Which antiepileptic drug induced cytochrome P450
Phenytoin
Tamoxifen mode of action
Selective estrogen receptor modulator
Contraindicated antimalarial in pregnancy
Doxycycline
Primaquine
What are the eicosanoids
- prostaglandins
- prostacyclins
- thromboxane
- leukotreines
Fentanyl is approximately how many times more potent than morphine
100 times
Bromocriptine and Cabergoline are agonists of what receptor
D2
Cyclizine and Promethazine mode of action
Histamine H1-receptor antagonist
Lidocaine acting by blocking what?
Fast Voltage gated sodium channels
Lidocaine half-life
2 hours
Maximum dose of Lidocaine
3 mg/kg
Maximum dose of lidocaine with adrenaline
7mg/kg
Two most common Dihydrofolate reductase inhibitor
Methotrexate
Trimethoprim
Antidote of Heroin
Naloxone
Ramipril side effects
-IUGR
-Renel dysgenesis
(ACEI)
LFT, RFT and Blood tests, in initiation Methotrexate ttt?
every 1-2 weeks
LFT, RFT and Blood tests, in established Methotrexate ttt?
2-3 months
What percent of patients allergic to penicillin will be allergic to cephalosporin
10%
Most common side effects of OAB therapy
Dry mouth = 1 in 10 patients
1st line ttt of OAB
-Oxybutynin
-Tolterodin
-Darifencain
Which method of contraception reduces the effect of Lamotrigine?
Estrogen component of contraception
(NOT PROGESTERON)
Resume COCs after Abortions and Birth giving
After Abortion immediately
After delivery if not breastfeeding with 3 weeks
Mode of action of Mefenamic Acid
Prostaglandin synthesis inhibitor
Choanal Atresia is a side effect of what drug
Carbimazol
LMWH is monitored by
Anti-factor Xa activity
First line ovulation induction (ttt of PCO)
Letrozol
(Less risk of multiple pregnancy)
Ovulation induction drugs
1- Letrozole #1
2- Gonadotrophins #2
3- Metformin
4- Clomiphene Citrate
Phase 2 reaction of drug metabolism
Conjugation
Hematological action of Prostacyclin PGI2
Inhibit platelet aggregation
Hematological action of Thromboxane TXA2
Induce platelet aggregation