Medicines 22 Flashcards
What are the half lifes of a drug in percentages?
⏳ 0 hours → 100%
📌 1 half-life → 50%
📌 2 half-lives → 25%
📌 3 half-lives → 12.5%
📌 4 half-lives → 6.25%
📌 5 half-lives → ~3% (considered eliminated)
What is 1st line treatment for VTE prophylaxis?
“Offer pharmacological VTE prophylaxis for a minimum of 7 days to acutely ill medical
patients whose risk of VTE outweighs their risk of bleeding: Use LMWH as first-line
treatment. If LMWH is contraindicated, use fondaparinux sodium”
What is a key caution with the combined oral contraceptive?
Risk of venous thromboembolism
There is an increased risk of venous thromboembolic disease in users of combined hormonal contraceptives particularly during the first year and possibly after restarting combined hormonal contraceptives following a break of four weeks or more. This risk is smaller than that associated with pregnancy and the postpartum period. In all cases the risk of venous thromboembolism increases with age and in the presence of other risk factors, such as obesity. The risk also varies depending on the type of progestogen and oestrogen dose.
Risk of cardiovascular disease
Combined hormonal contraceptives also slightly increase the risk of cardiovascular disease such as myocardial infarction and ischaemic stroke; risk appears to be greater with higher oestrogen doses.
What are the directions for administration for the combined hormonal contraceptive?
FSRH advises if reasonably certain woman is not pregnant, first course can be started on any day of cycle—if starting on day 6 of cycle or later, additional precautions (barrier methods) necessary during first 7 days; for estradiol-containing preparations, additional precautions (barrier methods) necessary for 7 days (9 days for Qlaira®) if started after day 1 of cycle.
What key travel information is required for the combined oral contraceptive?
Travel
Women taking oral contraceptives or using the patch or vaginal ring are at an increased risk of deep vein thrombosis during travel involving long periods of immobility (over 3 hours). The risk may be reduced by appropriate exercise during the journey and possibly by wearing graduated compression hosiery.
What is the advice around missed pilles with the COC?
Missed pill
With oral use:
The critical time for loss of contraceptive protection is when a pill is omitted at the beginning or end of a cycle (which lengthens the pill-free interval).
If a woman forgets to take a pill, it should be taken as soon as she remembers, and the next one taken at the normal time (even if this means taking 2 pills together). A missed pill is one that is 24 or more hours late. If a woman misses only one pill, she should take an active pill as soon as she remembers and then resume normal pill-taking. No additional precautions are necessary.
If a woman misses 2 or more pills (especially from the first 7 in a packet), she may not be protected. She should take an active pill as soon as she remembers and then resume normal pill-taking. In addition, she must either abstain from sex or use an additional method of contraception such as a condom for the next 7 days. If these 7 days run beyond the end of the packet, the next packet should be started at once, omitting the pill-free interval (or, in the case of everyday (ED) pills, omitting the 7 inactive tablets).
Emergency contraception is recommended if 2 or more combined oral contraceptive tablets are missed from the first 7 tablets in a packet and unprotected intercourse has occurred since finishing the last packet.
Why is acrivastine non-sedating?
The newer second-generation antihistamines include acrivastine cause less sedation
due to a higher water solubility with reduced blood brain barrier crossover.
For clozapine what is the treatment cessation advise?
For all antipsychotic drugs
There is a high risk of relapse if medication is stopped after 1–2 years. Withdrawal of antipsychotic drugs after long-term therapy should always be gradual and closely monitored to avoid the risk of acute withdrawal syndromes or rapid relapse. Patients should be monitored for 2 years after withdrawal of antipsychotic medication for signs and symptoms of relapse.
Treatment cessationFor clozapine
On planned withdrawal reduce dose over 1–2 weeks to avoid risk of rebound psychosis. If abrupt withdrawal necessary observe patient carefully.
What monitoing is required with clozapine?
📌 General Monitoring (All Antipsychotics)
🔹 Prolactin: Baseline, 6 months, then yearly
🔹 Schizophrenia Patients: Annual physical health & cardiovascular risk assessment
🔹 Blood Lipids & Weight: Baseline, 3 months, then yearly
🔹 Fasting Blood Glucose: Baseline, 4–6 months, then yearly
📌 Clozapine-Specific Monitoring
🔹 White Blood Cell Monitoring:
Weekly (first 18 weeks)
Fortnightly (up to 1 year)
Monthly (after 1 year)
🔹 Blood Clozapine Concentration: Monitor in specific clinical situations
🔹 Blood Lipids & Weight: Every 3 months (1st year), then yearly
🔹 Fasting Blood Glucose:
Baseline
1 month after starting
Every 4–6 months
🔹 Close Supervision During Initiation (Risk of hypotension & convulsions)
What can mineralcorticoids and glucocorticoids cause as side effects?
Mineralocorticoids can cause hypertension, sodium retention, water retention,
potassium loss and calcium loss.
Glucocorticoids can cause diabetes, osteoporosis, avascular necrosis of the femoral
head, muscle wasting, peptic ulceration/perforation, and psychiatric reactions.
What kind of laxative is sodium picosulfate?
stimulant laxatives and work through
biotransformation using gut flora to stimulate the large intestine motility.
How long after stopping an an antidepressant must the patient wait before starting
MAOI like phenylzine or vice versa?
at least 2 weeks after a previous MAOI has been stopped (then started at a reduced dose)
at least 7–14 days after a tricyclic or related antidepressant (3 weeks in the case of clomipramine or imipramine) has been stopped
at least a week after an SSRI or related antidepressant (at least 5 weeks in the case of fluoxetine) has been stopped
What important common side effect can occur with fluorouracil?
The administration of fluorouracil has been associated with the occurrence of palmar-
plantar erythrodysesthesia syndrome, also known as hand-foot syndrome. This is
listed as a common side effect in the BNF.
Continuous-infusion fluorouracil may increase the incidence and severity of palmar-
plantar erythrodysesthesia. This syndrome has been characterized as a tingling
sensation of hands and feet, which may progress over the next few days to pain when
holding objects or walking. The palms and soles become symmetrically swollen and
erythematous with tenderness of the distal phalanges, possibly accompanied by
desquamation. Interruption of therapy is followed by gradual resolution over 5 to 7
days
Which anticoagulant can be used with Phenytoin?
Phenytoin has interaction with DOACs leading to decreased anticoagulation effect.
Therefore warfarin is most appropriate option.
Which parameters are monitored with lithium every 6 months?
BNF recommends monitoring body weight/BMI, serum electrolyte, eGFR, thyroid
function every 6 months.
What is the most appropriate insuline to give in a DKA?
“soluble insulin administered intravenously is the most
appropriate form of insulin for use in diabetic ketoacidosis”
What are the symptoms of Cauda equina syndrome?
Symptoms of cauda equina syndrome:
Severe low back pain.
Motor weakness, sensory loss, or pain in one or commonly both legs.
Saddle anaesthesia (unable to feel anything in the body areas that sit on a
saddle)
Bladder dysfunction (such as urinary retention or incontinence)
Bowel incontinence.
What are the symptoms of an ectopic pregnancy?
📌 Main Symptoms
🔹 Missed period, positive pregnancy test, & other pregnancy signs
📌 Warning Signs – Seek Medical Help If:
🔹 Vaginal Bleeding – Irregular, dark brown, watery, starts & stops
🔹 Tummy Pain – Low down, usually on one side, sudden or gradual
🔹 Shoulder Tip Pain – Unusual pain at shoulder-arm junction (possible internal bleeding)
🔹 Discomfort When Using Toilet – Pain/pressure during urination or bowel movements, diarrhoea
📌 Symptoms of a Rupture (Emergency 🚨)
🔹 Severe, sharp tummy pain (sudden & intense)
🔹 Dizziness or fainting
🔹 Nausea or vomiting
Which antidiabetic drug is contraindicated in heart failure?
Pioglitazone
What are the first line antihypertensives in pregnancy?
Labetalol is recommended first-line in pregnant women with pre-eclampsia,
gestational or chronic hypertension presenting with a sustained blood pressure of
140/90 mmHg or higher.
Nifedipine can be considered (unlicensed) if labetalol is unsuitable.
Methyldopa can be considered (unlicensed) if both labetalol and nifedipine are
unsuitable.
If someone develops a cough whilst taking an ACE what do you switch them to?
an ARB
What monitoring is required with Tacrolimus?
📌 Therapeutic Drug Monitoring (TDM)
✔️ Adjust dose based on whole blood-tacrolimus trough concentrations
✔️ Monitor closely during diarrhoea (can affect absorption)
✔️ Black African/African-Caribbean patients may need higher doses
✔️ Follow local treatment protocols for TDM guidance
📌 Patient Monitoring (Systemic Use)
✅ Blood pressure
✅ ECG (check for cardiomyopathy)
✅ Fasting blood glucose
✅ Full blood count & coagulation parameters
✅ Plasma protein & electrolytes
✅ Neurological status (including vision)
✅ Liver & kidney function
What key counselling points are there with Tacrolimus ?
📌 Key Patient Counseling Points:
✅ Take at the same time daily
✅ Avoid grapefruit & alcohol
✅ Report any signs of infection (fever, sore throat)
✅ Tacrolimus is brand-specific
What are the indications for Tacrolimus?
✔️ Prevention of organ transplant rejection (kidney, liver, heart)
✔️ Treatment of graft-versus-host disease (GVHD)
✔️ Topical Tacrolimus – For moderate-to-severe atopic dermatitis (eczema) unresponsive to steroids
