Drugs

PPIs

Names: Omeprazole and Pantoprazole

Metformin

Names: Metformin

Incretin-based Therapies

Names: Semaglutide and Sitagliptin

SGLT2i

Names: Empagliflozin and Dapagliflozin

Insulin

Names: Insulin glargine and Insulin Aspart

HRT

Names: Estradiol and Medroxyprogesterone

Contraceptive pills

Names: Ethinylestradiol and Levonorgestrel

Thyroxine

Names: Levothyroxine (T4) and Liothyronine (T3)

Corticosteroids

Names: Prednisolone and Dexamethasone

Anti-resorptive

Names: Alendronate and Denosumab

PPI

Mechanism: Irreversibly inhibits proton pump in the parietal cells which reduces acid secretion and allows esophageal lining to heal.

Metformin

Mechanism: Works by reducing glucose production in liver and helping body use insulin more effectively. This lowers blood sugar levels without causing hypoglycaemia

Incretin-based Therapies

Mechanism: GLP-1 increases insulin release when blood sugar is high, reducing glucagon release, slowing stomach emptying and reducing appetite.

DPP-4i blocks the DPP-4 enzyme which increases incretin levels, leading to more insulin release and less glucagon release when blood sugar is high, lowering blood glucose levels.

SGLT2i

Mechanism: Makes kidney remove glucose in the urine, lowering BP. Can cause some weight loss and lower BP because loss of salt water.

Insulins

Mechanism: Binds to insulin receptors and increases glucose uptake into muscle and decrease glucose production in liver, lowering blood glucose levels as a result.

HRT

Mechanism: Produces hormones lost in menopause. Helps with hot flushes, night sweats, vaginal symptoms, and protects bone health. Progesterone is added to protect uterus

Contraceptive pills

Mechanism: Pill prevents ovulation, blocks sperm by thickening cervical mucus, and makes uterus less suitable for pregnancy.

Thyroxine

Mechanism: T4 is converted to T3 in the body and binds to Thyroid receptors to restore normal metabolism, growth, and CV functions.

Corticosteroids

Mechanism: Mimics effects of cortisol, reducing inflammation and suppressing immune response.

Anti-resorptive

Mechanism: Aldenronate slows down osteoclasts which breakdown bone, which reduces bone loss and helps it become stronger.

Denosumab blocks RANKL that osteclasts need to grow and work, which mean fewer osteoblasts form, so less bone breaks down and make it stronger.PPI

PPI

Clinical Indications:

Mono —> GORD, Peptic ulcer disease, Dyspepsia
Combo —> Upper GI bleeding

Thyroxine

Clinical indications:

Mono —> Hypothyroidism, post-thyroidectomy, suppression therapy in thyroid cancer.
Combo —> Occasionally combined with liothyronine in resistant hypothyroid symptoms (specialist-only)

Anti-resorptive

Clinical indications:

Mono —> Osteoporosis, and Fracture prevention
Combo —> Ca + VitD supplements + Anti-resorptive

Contraceptive pills

Clinical indications:

Mono —> Contraceptions, irregular periods, heavy menstrual bleeding
Combo —> Used with antibiotics or other drugs not related to conception.

HRT

Clinical indications:

Mono —> Menopause symptom relief, prevention of post-menopausal osteoporosis, premature ovaria insufficiency
Combo —> Oestrogen + Progestogen if uterus present, Oestrogen alone if hysterectomy is preformed.

Metformin

Clinical indications:

Mono —> First-line treatment of Type 2 diabetes
Combo —> Metformin + Empagliflozin, Dapagliflozin, Insulin, Semaglutide

Incretin-based therapies

Clinical indications:

Mono —> Type 2 diabetes (when metformin not tolerated)
Combo —> Commonly used with metformin, insulin, SGLT2i.
Weight management for obesity.

SGLT2i

Clinical indications:

Mono —> Type 2 diabetes (when metformin not tolerated)
Combo —> SGLT2i + Metformin (first-line combo) , Insulin , GLP-1

Insulins

Clinical indications:

Mono —> Type 1 diabetes , Acute Type 2 diabetes (acute illness/hospitilization), DKA
Combo —> Insulin + Metformin for Type 2 diabetes, with GLP-1 or SGLT2i in advanced disease.

Corticosteroids

Clinical indications:

Mono —> Asthma, COPD, Allergies, Inflammatory conditions, cerebral oedema.

PPIs

Common side effects:

Headache, nausea, Diarrhea, Constipation

Thyroxine

Common side effects:

Anxiety, tremor, weight loss, palpitations.

Anti-resorptive

Common side effects:

Alendronate: Abdo pain, nausea, acid reflux

Denosumab: Skin infections, mild hypocalacaemia

Contraceptive pills

Common side effects:

Nausea, headache, mood changes, breast tenderness

HRT

Common side effects:

Nausea, Bloating, Headache, mood changes, breast tenderness

Metformin

Common side effects:

GI side effects (Nausea, vomiting, diarrhoea, bloating)

Incretin-based therapies

Common side effects:

Semaglutide: Nausea, vomiting, diarrhoea, reduced appetite
Sitagliptin: Headache, mild GI upset, joint pain

SGLT2i

Common side effects:

Increased urination and thirst, mild dehydration, UTIs.

Insulins

Common side effects:

Hypoglycaemia, weight gain, lipohypertrophy, mild oedema.

Corticosteroids

Common side effects:

Insomnia, indigestion, fluid retention.

PPIs

Major clinically significant side effects:

Long-term use of VB12 and Fe deficiency, increased fracture risk due to reduced Ca absorption.

PPIs

Route of administration:

Oral tablets, capsules,
IV when oral not possible or GI bleeding

PPIs

Clinically significant drug interactions:

Clopidogrel (Omeprazole inhibits CYP2C19 and Clopidogrel)
Warfarin (Increased bleeding risk)
Methotrexate (Reduced clearance and increased toxicity risk)

PPIs

Important counselling/practice points:

Take 30-60mins before meals (brekkie preferred)
Use lowest effective dose
Long-term therapy should be monitored
Report black stools, unexplained weight loss, and difficulty swallowing.

PPIs

Use in Preg/BF:

Preg: Generally safe when clinically indicated
BF: Generally compatible, small amounts enter breast milk.

PPIs

Limitations in therapy:

Children: Can be used with paediatric patients, dosing weight-based, specialist use only.
Elderly: Increased risk of long-term adverse effects.
Renal impairment: No dose adjustment required.
Hepatic impairment: Severe impairment may need dose reduction.
Contraindication: Hypersensitivity to PPIs.

PPIs

Important differences between drugs:

Omeprazole: More CYP2C19 inhibition, interact with clopidogrel
Pantoprazole: Fewer CYP2C19 interaction, preferred with patients taking clopidogrel.

PPIs

Monitoring:

Healing of oesophagitis or ulcers, reflux symptoms.
Long-term: VB12 status, Fe status, Renal function
Persistent diahrroea, sign of infection, fractures.

Thyroxine

Major clinically significant side effects:

Overtreatment leads to AF, tachycardia, osteoporosis
Serious —> Thyrotoxic crisis

Thyroxine

Route of administration:

Oral tablets and IV (emergency myxoedema coma)

Thyroxine

Clinically significant drug interactions:

PPI —> Omeprazole reduces gastric acidity and lowers absorption rate
Ca and Fe supplements —> reduces absorption of levothyroxine in gut
Warfarin —> Thyroxine increases metabolism of clotting factors

Thyroxine

Important counselling/practice points:

Take on empty stomach 30-60min before food
Take same time daily (morning recommended)
Avoid Ca/Fe
Report palpitations, tremor, insomnia

Thyroxine

Use in Preg/BF:

Preg: Safe/essential; increase dose; poor control increases risk of fetal neurodevelopment
BF: Safe, minimal transfer into milk

Thyroxine

Limitations in therapy:

Children: Essential for growth/neurodevelopment; dose weight-based
Elderly: Start low go slow; higher risk of cardiac complications
Renal impairment: No dose adjustment required
Hepatic impairment: No dose adjustment required
Contraindications: Untreated adrenal insufficiency and thyrotoxicosis

Thyroxine

Important difference between drugs:

Levothyroxine —> First inline, Long half-life (~7 days), converts to T3 in body, stable once daily dosing
Liothyronine —> Shorter half-life, more rapid/potent effect, higher risk of cardiac effects, specialist use only

Thyroxine

Monitoring:

TSH, Free T4 levels, HR in elderly, Bone density, Pregnant thyroid function

Anti-resorptive

Major clinically significant side effects:

Osteonecrosis of Jaw
Alendronate: Oesophagitus, oesophageal carcinoma,
Denosumab: Sever hypocalacaemia, rebound vertebral fractures

Anti-resorptive

Route of administrations:

Alendronate: Weekly oral
Denosumab: 6 monthly subcutaneous injection

Anti-resorptive

Clinically significant drug interactions:

PPIs —> Reduce Ca absorption
Corticosteroids —> Additive risk of osteoporosis
Ca/Antacids —> Reduce absorption of alendronate

Anti-resorptive

Important counselling/practice points:

Alendronate: Take first thing on morning on empty stomach, full glass of water, upright for 30-60mins and no food or drink, dont crush or chew tablet
Denosumab: Ensure adequate Ca/Vit D intake, report infection, don’t miss scheduled injections.

Anti-resorptive

Use in Preg/BF:

Preg: Not recommended
BF: Avoid

Anti-resorptive

Limitations in therapy:

Children: Specialist only
Elderly: Used in osteoporosis, monitor Ca and renal function
Renal impairment: No alendronate, can use denosumab but high risk of hypocalacaemia
Hepatic impairment: No dose adjustment required
Contraindications: Alendronate with oesophageal disorders ; Denosumab with hypocalacaemia

Anti-resorptive

Important differences between drugs:

Alendronate: First in-line, Oral weekly tablets, GI irritation
Denosumab: Subcutaneous injections every 6 months, use if bisphosphonates not tolerated, high risk of hypocalacaemia

Anti-resorptive

Monitoring:

DEXA scan, serum Ca/Vit D, renal function, fracture risk assessment, signs of hypocalacaemia

Contraceptive pills

Major clinical side effects:

VTE, Stroke, hypertension, cholestatic jaundice

Contraceptive pills

Route of administration:

Oral tablets (daily)
Cyclic or continuous regimens depending on interaction.

Contraceptive pills

Clinically significant drug interactions:

Enzyme inducers —> Increases hepatic metabolism and lowers hormone levels
Antibiotics —> lowers contraceptive effect
St. John’s Wort —> lowers contraceptive hormone levels and increases risk of pregnancy

Contraceptive pills

Important counselling/practice points:

Take same time daily, missing pills increases pregnancy risk
Avoid smoking,
No protection against STI
Seek urgent help if chest pain, leg swollen, sudden shortness of breath

Contraceptive pills

Use in Preg/BF:

Preg: Contraindicated
BF: May reduce milk supply / Progestogen only in early BF

Contraceptive pills

Important differences between drugs:

Ethinylestradiol: Oestrogen component, main contributor to thrombotic risk
Levonorgestrel: Progestogen component, lowers thrombotic risk, responsible for ovulation suppression

Contraceptive pills

Monitoring:

BP, VTE symptoms, weight, migraine patterns, pregnancy test if missed pill

HRT

Major significant side effects:

VTE, Stroke, breast cancer risk, gall bladder disease

HRT

Route of administration:

Oral tablets, transdermal patches for VTE risk patients, topical vaginal preparations

HRT

Clinically significant drug interactions:

Enzyme inducers increase hepatic metabolism and lower HRT effectiveness
Thyroxine (Oestrogen increases thyroid-binding globulin)
Anticoagulants (Warfarin, requires close INR monitoring)

HRT

Important counselling/practice points:

Use lowest effective dose for shortest duration
Not a contraceptive
Report chest pain, leg swelling, shortness of breath
May take weeks for symptoms to improve

HRT

Use in Preg/BF

Preg: Stop if pregnancy occurs.
BF: Generally avoided postpartum, may reduce milk production

HRT

Limitations in therapy:

Children: Not used
Elderly: Higher CV/Cancer risk
Renal impairment: No dose adjustment required
Hepatic impairment: Avoid in severe liver disease
Contraindications: History of VTE, Breast cancer, unexplained vaginal bleeding, severe liver disease

HRT

Important differences between drugs:

Estradiol: Main oestrogen component, controls vasomotor symptoms and bone protection.
Methoxyprogesterone acetate: Main progesterone component, cause mood changes, essential combined HRT for women with uterus

HRT

Monitoring:

BP, Breast screening, Signs of VTE, Vaginal bleeding patterns, Bone density if osteoporosis risk

Metformin

Major clinical side effects:

Lactic acidosis (severe weakness, abdominal pain, rapid breathing)
VB12 deficiency (anaemia, fatigue, peripheral neuropathy)

Metformin

Route of administration:

Oral immediate/modified release tablets

Metformin

Clinically significant drug interactions:

Iodinated contrast media —> may cause acute kidney injury
Alcohol —> increase lactate production and lactic acidosis risk
NSAIDs/Diuretics —> Kindey injury may reduce metformin clearance
Insulin —> increase risk of hypoglycaemia

Metformin

Important counselling/practice points:

Take with food and hydrate
GI effects are common initially
Dont stop unless advised
Seek medical attention for vomiting, diarrhoea, and dehydration

Metformin

Use in Preg/BF:

Preg: Insulin is preferred; Metformin used in gestational and T2 diabetes
BF: Compatible; only small amounts enter milk

Metformin

Limitations in therapy:

Children: Use on children with T2D; risk of accumulation
Elderly: Monitor renal function; dose reduction as kidney function declines
Renal impairment: Safe in mild renal impairment; dose reduction as kidney function declines
Hepatic impairment: Avoid; risk of lactic acidosis
Contraindications: Severe renal impairment, hypersensitivity, DKA

Metformin

Important differences between drugs:

IR: Taken 2-3 times daily, more GI side effects
MR: Once daily, better GI tolerability, improved adherence

Metformin

Monitoring:

HbA1c every 3-6 months, blood glucose levels, renal function, VB12 (Anaemia and neuropathy), weight.