Medicines 2

Question 1

WHat medications does trimethoprim interact with?

Answer 1

Drugs:

ACE inhibitors, ARBs, spironolactone – increased risk of hyperkalaemia
Amiodarone – increased risk of ventricular arrhythmias when trimethoprim (as co-trimoxazole) given with amiodarone—manufacturer of amiodarone advises avoid with co-trimoxazole
Azathioprine – increased risk of haematological toxicity
Ciclosporin, Tacrolimus – increased risk of nephrotoxicity when trimethoprim given with ciclosporin, also plasma concentration of ciclosporin reduced by intravenous trimethoprim
Coumarins – enhances anticoagulant effect by killing normal gut flora that synthesis vitamin K
Digoxin – increased concentrations of digoxin
Phenytoin – increases plasma concentration of Phenytoin (also increased antifolate effect)
Methotrexate – increased risk of severe bone marrow depression (fatalities reported) and other haematological toxicities
Repaglinide – enhances hypoglycaemic effect – avoid

Question 1

What counselling point should be given for trimethoprim?

Answer 1

Counselling

Look out for signs of blood disorders in long term use: fever, sore throat, rash, mouth ulcers, purpura, bruising or bleeding develop.

Question 2

What medications interact with amoxicillin?

Answer 2

Drugs:

Allopurinol – increased risk of rash
Coumarins – INR may be altered, enhance anticoagulant effect by killing normal gut flora that synthesise vitamin K
Methotrexate – penicillin reduce excretion of methotrexate – increased risk of toxicity
Tetracyclines – effects of penicillins possibly antagonised by tetracyclines
Typhoid vaccine – antibacterial inactivate oral typhoid vaccine

Question 3

What are key cautions and contraindications for macrolides ?

Answer 3

Cautions and contraindications; conditions

Avoid in history of macrolide hypersensitivity
Caution in severe hepatic impairment
Reduce dose in severe renal impairment

Question 4

How long do glycerol suppositories take to work?

Answer 4

Explanation: Glycerol suppositories work within 15-30 minutes. It is a stimulant laxative.

Question 5

What is prucalopride?

Answer 5

Prucalopride is a selective serotonin 5HT4-receptor agonist used for chronic constipation when other laxatives are ineffective.

Question 7

How long does senna take to have effect

Answer 7

Doesn’t work immediately will take 8-12 hours so take dose at night

Question 8

What are the different types of laxatives, how do they work and give two examples for each

Answer 8

Bulk-Forming Laxatives:

Mechanism: They absorb water into the stool, increasing its bulk and making it easier to pass.
Examples: Psyllium (e.g., Fybogel), Methylcellulose (e.g., Citrucel), Ispaghula husk (e.g., Metamucil).
Onset: Usually takes 12-72 hours.

Stimulant Laxatives:

Mechanism: They stimulate the muscles in the intestines to contract, speeding up bowel movements.
Examples: Senna (e.g., Senokot), Bisacodyl (e.g., Dulcolax), Sodium picosulfate (e.g., Picolax).
Onset: Typically works within 6-12 hours.

Osmotic Laxatives:
Mechanism: They draw water into the bowel, softening stool and making it easier to pass.
Examples: Lactulose (e.g., Duphalac), Macrogol (e.g., Movicol, Miralax), Magnesium hydroxide (e.g., Milk of Magnesia).
Onset: Generally works within 24-48 hours, but magnesium-based laxatives may work faster.

Stool Softeners (Emollient Laxatives):
Mechanism: They soften the stool by allowing water and fats to penetrate it, making it easier to pass.
Examples: Docusate sodium (e.g., Colace, DulcoEase).
Onset: Typically takes 1-3 days to work.

Prokinetic Laxatives:

Mechanism: They enhance the motility of the gastrointestinal tract to help move stool through.
Examples: Prucalopride (e.g., Resolor), typically used for chronic constipation when other laxatives haven’t worked.
Onset: May take a few days to show effects.

Question 9

What are counselling points regarding lactulose?

Answer 9

Counselling
Not to be given in IBS
Will make stool softer and easier to pass
Must drink plenty of water – 6-8 glasses a day
If regularly passing more than 2-3 soft stools per day he dose should be reduced or stopped
Can take up to 48 hours to have an effect
Eating a healthy diet, drinking plenty of water and getting regular gentle exercise can all help prevent constipation.
15ml (3x5ml spoons) twice daily

Question 10

WHat is the treatment for severe ulcerative colitis?

Answer 10

Explanation: Acute severe ulcerative colitis of any extent can be life-threatening and is regarded as a medical emergency. Intravenous corticosteroids (such as hydrocortisone or methylprednisolone) should be given initially to induce remission in patients with acute severe ulcerative colitis (at first presentation or an exacerbation) while assessing the need for surgery. Only if intravenous corticosteroids are contra-indicated, declined or cannot be tolerated, then intravenous ciclosporin [unlicensed indication] or surgery should be considered. A combination of intravenous ciclosporin with intravenous corticosteroids, or surgery is second line therapy for patients who have little or no improvement within 72 hours of starting intravenous corticosteroids or whose symptoms worsen despite treatment.

Infliximab can be used to treat acute exacerbations of severely active ulcerative colitis if ciclosporin is contra-indicated or clinically inappropriate.

Question 11

What is mebeverine used for?

Answer 11

Explanation: Mebeverine is used for the symptomatic treatment of irritable bowel syndrome. It is a direct-acting intestinal smooth muscle relaxant and may relieve abdominal pain or spasm in irritable bowel syndrome.

Question 12

What is Octasa (mesalazine) and what is a key counselling point regarding it?

Answer 12

Mesalazine (also known as 5-aminosalicylic acid, or 5-ASA) is an anti-inflammatory medication used primarily to treat inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn’s disease. It helps to reduce inflammation in the intestines, thereby alleviating symptoms like diarrhea, abdominal pain, and bleeding.

Mechanism of Action:
Mesalazine works by inhibiting the production of pro-inflammatory chemicals (such as prostaglandins and leukotrienes) in the gut. This action reduces inflammation in the lining of the intestines, helping to manage flare-ups in conditions like ulcerative colitis and Crohn’s disease.

Explanation: Serious blood dyscrasias have very rarely been reported with Octasa. Therefore therapy should be stopped immediately if there is suspicion or evidence of blood dyscrasias. This includes signs of unexplained bleeding, bruising, purpura, anemia, persistent fever or sore throat, and patients should seek immediate medical advice.

The tablets must be swallowed whole, not crushed, as they are modified release tablets, preferably with some liquid before food intake. Octasa acts locally at the site of inflammation (colon, rectum and terminal ileum) to reduce inflammation.

Patients allergic to penicillin are fine with Octasa, however mesalazine should be avoided with patients that are allergic to salicylates (e. g. aspirin).

Patients taking Octasa need to ensure they drink adequate fluids to remain well hydrated, especially after severe or prolonged episodes of vomiting and/or diarrhoea, high fever or heavy sweating. This is to avoid renal problems.

Question 13

What are the different antihistamines used orally in the UK and what is their dosage?

Answer 13

1. First-Generation Antihistamines
   These are older medications that can cause drowsiness due to their ability to cross the blood-brain barrier. They are often used for short-term relief of symptoms.

Chlorphenamine (also called Chlorpheniramine)
Dosage:
Adults: 4 mg every 4–6 hours (up to 24 mg per day)
Children (6-12 years): 2 mg every 4-6 hours (up to 12 mg per day)
Children (2-6 years): 1 mg every 4–6 hours (up to 6 mg per day)
Common brands: Piriton

Diphenhydramine
Dosage:
Adults: 25–50 mg every 4-6 hours (up to 300 mg per day)
Children (6-12 years): 12.5–25 mg every 4-6 hours
Common brands: Benadryl

Promethazine
Dosage:
Adults: 25 mg at bedtime or 10 mg every 4–6 hours if needed
Children (6-12 years): 5–10 mg every 4-6 hours
Common brands: Phenergan
2. Second-Generation Antihistamines
These are newer, less sedating antihistamines that are less likely to cause drowsiness and are often preferred for long-term management of allergic conditions.

Loratadine
Dosage:
Adults and children (over 12 years): 10 mg once daily
Children (2–12 years): 5 mg once daily
Common brands: Claritin, Clarityn

Cetirizine
Dosage:
Adults and children (over 6 years): 10 mg once daily
Children (2–6 years): 2.5 mg once daily (can be increased to 5 mg if needed)
Common brands: Zyrtec, Benadryl (non-drowsy)

Fexofenadine
Dosage:
Adults and children (over 12 years): 120 mg once daily or 180 mg once daily
Children (6-12 years): 30 mg twice daily
Common brands: Telfast

Acrivastine Dosage (Orally):
Adults and Children (over 12 years):
The typical dose is 8 mg (1 tablet) three times a day.
Maximum dose: Do not exceed 24 mg per day (3 tablets).
Children (under 12 years):
Acrivastine is not generally recommended for children under 12 years of age, as safety and efficacy have not been well-established for younger children

Desloratadine
Dosage:
Adults and children (over 12 years): 5 mg once daily
Children (6-12 years): 2.5 mg once daily
Common brands: Aerius

Levocetirizine
Dosage:
Adults and children (over 6 years): 5 mg once daily
Children (2-6 years): 1.25 mg once daily
Common brands: Xyzal

Question 14

What inhaler device is umeclidinium only found in?

Answer 14

Umeclidinium is only available in an Ellipta type of device.

Question 15

This particular inhaler should be prescribed by brand. Which one of the above inhalers should be prescribed by brand?

Answer 15

Explanation: Beclometasone dipropionate CFC free inhalers should be prescribed by brand name. For example Qvar is more potent than traditional inhalers e.g Clenil Modulite. Qvar has extra fine particles making it more potent.

Beclometasone dipropionate CFC-free pressurised metered-dose inhalers and not interchangeable. Qvar has extra-fine particles and is more potent than traditional Beclometasone dipropionate CFC-free pressurised metered-dose inhalers and probably twice as potent as Clenil Modulite.

Question 16

What are mucolytics and how do they work?

Answer 16

Mucolytics are medications that thin and break down mucus in the respiratory tract, making it easier to cough up and clear from the airways

Acetylcysteine (e.g., Fluimucil, Parvolex):

Dosage: Usually given orally or inhaled, acetylcysteine works by breaking down the chemical bonds in mucus, making it less viscous. It is commonly used for chronic respiratory conditions like COPD, bronchitis, and cystic fibrosis.
Inhalation: For conditions like COPD, it is often inhaled to act directly in the lungs.
Oral: It can also be used to treat paracetamol (acetaminophen) overdose, as it helps to restore glutathione levels in the liver.
Carbocisteine (e.g., Mucodyne, Mucomyst):

Dosage: Oral form, usually given two or three times a day. It works similarly to acetylcysteine by reducing the viscosity of mucus and making it easier to clear.
Indications: Used in chronic respiratory conditions like COPD and chronic bronchitis.

Question 17

How do mucolytics affect the GI barrier?

Answer 17

Mucolytics can disrupt the gastric mucosal barrier and therefore is contra-indicated in those with active peptic ulceration.

Question 18

What is the target concentration for theophylline?

Answer 18

most individuals, a plasma-theophylline concentration of 10–20 mg/litre (55–110 micromol/litre) is required for satisfactory bronchodilation, although a lower plasma-theophylline concentration of 5–15 mg/litre may be effective. Adverse effects can occur within the range 10–20 mg/litre and both the frequency and severity increase at concentrations above 20 mg/litre.

Question 19

How can oral thrush be avoided with inhalers?

Answer 19

Oral thrush can be avoided by rinsing the mouth after use of steroid containing inhalers. This can occur with prolonged steroid use which can depress the immune system.

Question 20

What medications does methotrexate interact with?

Answer 20

Drugs:

Aspirin or NSAIDs, penicillins, indomethacin, ketoprofen, PPIs – dose of methotrexate should be carefully monitored = excretion of methotrexate reduced = inhibit its renal excretion
Acitretin – plasma concentration of methotrexate increased by acitretin (also increased risk of hepatotoxicity)—avoid = used for treatment of psoriasis
Ciclosporin – risk of toxicity
Cisplatin – increased pulmonary toxicity
Digoxin – possibly reduces absorption of digoxin tablets
Levetiracetam – plasma concentration of methotrexate possibly increased
Nitrous oxide – antifolate effect of methotrexate increased – avoid
Phenytoin – antifolate effect of methotrexate increased by phenytoin
Trimethoprim – increased risk of severe bone marrow depression (fatalities reported) and other haematological toxicities when methotrexate given with trimethoprim (also with co-trimoxazole) and sulfamethoxazole = it is also a folate antagonist
Clozapine – avoid concomitant use of cytotoxics with clozapine (increased risk of agranulocytosis)

Question 21

What monitoring requirements are there for methotrexate?

Answer 21

Monitoring

Exclude pregnancy before treatment
Monitor full blood count, renal and liver function tests before starting treatment
In view of reports of blood dyscrasias (including fatalities) and liver cirrhosis with low-dose methotrexate patients should:
Have full blood count and renal and liver function tests repeated every 1–2 weeks until therapy stabilises, thereafter patients should be monitored every 2–3 months.
Be advised to report all symptoms and signs suggestive of infection, especially sore throat
Local protocols for frequency of monitoring may vary.
Treatment with folinic acid (as calcium folinate) may be required in acute toxicity.

Question 22

What counselling points are there for methotrexate?

Answer 22

Counselling

Patients and their carers should be warned to report immediately the onset of any feature of blood disorders (e.g. sore throat, bruising, and mouth ulcers), liver toxicity (e.g. nausea, vomiting, abdominal discomfort and dark urine), and respiratory effects (e.g. shortness of breath).
Patients should be advised to avoid self-medication with over-the-counter aspirin or ibuprofen.
Patients should be counselled on the dose, treatment booklet, and the use of NSAIDs.
TAKE ONCE A WEEK on the same day each week
Take folic acid on a different day to methotrexate also one a week
Use effective contraception

Question 23

what is Recombinant human granulocyte-colony stimulating factor (rhG-CSF)

Answer 23

Recombinant human granulocyte-colony stimulating factor (rhG-CSF) stimulates the production of neutrophils. It is indicated for the reduction in duration of neutropenia and incidence of febrile neutropenia in cytotoxic chemotherapy for malignancy. Human G-CSF is a glycoprotein which regulates the production and release of functional neutrophils from the bone marrow. rhG-CSF causes marked increases in peripheral blood neutrophil counts within 24 hours, with minor increases in monocytes.

Question 24

What food warnings are required for ciclosporin

Answer 24

Avoid pomelo juice, grapefruit and grapefruit juice, as these can increase ciclosporin levels in the blood and increase the risk of side effects.

Avoid alcohol or limit consumption, as it can strain the liver, which is already under added pressure from the medication.

Question 25

What vitamin can be used to prevent Isoniazid induced peripheral neuropathy

Answer 25

Isoniazid induced peripheral neuropathy can be prevented and treated with pyridoxine (vitamin b6). It is usually given to all patients prophylactically at the start of treatment.

Question 26

What vitamin is recommended to prevent neural tube defects in pregnant ladies?

Answer 26

Folic acid (Vitamin B9)

Folic acid 400mcg is recommended up to 12 weeks of pregnancy to prevent neural tube defects.

Sometimes folic acid 5mg is recommended for example in a woman receiving antiepileptic medication.

Question 27

What vitamin is used to treat scurvy?

Answer 27

Ascorbic acid. Scurvy is rare now. It is due to vitamin C deficiency. It is prevented and treated with vitamin C.

Question 28

A 67 year old female was diagnosed with folate deficient anaemia following a routine blood test. She has a previous history of Stroke, and Diabetes Type 2. What is the duration of treatment with folic acid?

Answer 28

Treatment for 4 month and repeat bloods to see if folate levels have corrected.

Question 29

What is G6PD deficiency and who is most at risk?

Answer 29

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic condition that primarily affects red blood cells and increases vulnerability to certain medications, foods, infections, and other triggers that can cause hemolytic anemia (destruction of red blood cells). The deficiency occurs due to mutations in the G6PD gene, which is located on the X chromosome. Because of this, certain populations and groups are more at risk.

Populations at Higher Risk of G6PD Deficiency:
Geographic and Ethnic Groups:

African and African American Descent: G6PD deficiency is relatively common in people of African descent, particularly among males. About 10–15% of African American males in the United States have the condition.
Mediterranean Populations: Higher prevalence in people from Mediterranean countries, especially those of Greek, Italian, and Turkish descent.
Middle Eastern Populations: More common among people from the Arabian Peninsula, Iran, and Iraq.
South Asian Populations: Individuals from countries such as India and Pakistan are also at increased risk.
Southeast Asian Populations: More frequent in people from regions like the Philippines, Malaysia, Indonesia, and Thailand.
Gender:

Male: Since the G6PD gene is located on the X chromosome, males (who have one X and one Y chromosome) are more frequently affected. If they inherit a defective G6PD gene, they are likely to have the deficiency.
Female Carriers: Females have two X chromosomes, so they are less likely to be fully affected unless they inherit two copies of the mutated gene. However, females with one defective gene can be carriers, and some may show mild symptoms if they have partial enzyme deficiency.

Females are at lower risk than males, and the ethnicities most at risk are Asian, African, and South European.

Question 30

What are the symptoms of vitamin D deficiency?

Question 31

Which antimalarial medication can be used to treat Active rheumatoid arthritis

Answer 31

Chloroquine due to its anti-inflammatory and immunomodulatory effects. Originally developed as an antimalarial drug, chloroquine is classified as a disease-modifying antirheumatic drug (DMARD)

Question 32

What are the different type of DMARDs?

Answer 32

Conventional Synthetic DMARDs (csDMARDs)
These are traditional DMARDs that have been used for decades to manage RA and similar conditions. They work by broadly suppressing the immune system.

Methotrexate: The most commonly used csDMARD, it inhibits the enzyme dihydrofolate reductase, reducing inflammation.
Sulfasalazine: This anti-inflammatory drug is thought to work by suppressing the immune response.
Leflunomide: It inhibits pyrimidine synthesis, which reduces immune cell proliferation.
Hydroxychloroquine and Chloroquine: Originally antimalarials, they modulate immune response, reducing inflammation in autoimmune diseases.

Biologic DMARDs (bDMARDs)
Biologic DMARDs are derived from living organisms and target specific immune molecules or cells involved in inflammation. They are usually used when csDMARDs are ineffective. Types include:

TNF inhibitors: Block tumor necrosis factor (TNF), a key molecule in inflammation (e.g., adalimumab, infliximab, etanercept).
IL-6 inhibitors: Target interleukin-6 (IL-6), another inflammatory cytokine (e.g., tocilizumab).
B-cell inhibitors: Target B cells involved in autoimmune responses (e.g., rituximab).
T-cell costimulation inhibitors: Block the activation of T cells (e.g., abatacept).

Biological DMARDs include abatacept, sarilumab and tocilizumab. Biological DMARDs are more target specific.

Question 33

What is a key counselling point with latanoprost

Answer 33

Eye Color Changes: Latanoprost may gradually increase the brown pigmentation in the iris, leading to a permanent change in eye color, particularly in patients with mixed-color irises (e.g., blue-brown, green-brown). This effect is usually gradual and may not be reversible.

Eyelash and Eyelid Changes: It can cause eyelashes to grow longer, thicker, and darker, and may also lead to changes in eyelid skin pigmentation.

Application Technique: Instruct patients to apply only one drop to the affected eye(s) once daily in the evening, as more frequent use can reduce its effectiveness. They should avoid touching the dropper tip to the eye or any surface to prevent contamination.

Remove Contact Lenses: Latanoprost contains benzalkonium chloride, which can be absorbed by contact lenses. Patients should remove lenses before application and wait at least 15 minutes before reinserting them.

Transient Blurring: Vision may be temporarily blurred after application, so patients should wait until vision is clear before driving or operating machinery.

Storage: Before opening, keep the bottle in the refrigerator. Once opened, it can be stored at room temperature for up to six weeks.
unless Xalatan

Question 34

What are the classic symptoms of glaucoma?

Answer 34

Typical symptoms and signs of glaucoma include: eye pain, often severe, and associated with headache, nausea, and vomiting caused by the pain. A red eye. Impaired visual acuity and lights are seen surrounded by halos. Semi-dilated and fixed pupil. Classically, the pupil becomes fixed in a vertically oval shape. A tender, hard eye (palpate very gently). When measured by an optometrist or ophthalmologist, the intraocular pressure (IOP) is typically very high.

Question 35

WHat are the different treatments for psoriasis?

Answer 35

Topical Treatments
For mild to moderate psoriasis, topical treatments are often the first line of therapy. These are applied directly to the skin to help reduce inflammation, scaling, and plaque formation.

Corticosteroids: Commonly used to reduce inflammation and itching (e.g., hydrocortisone, betamethasone).
Vitamin D Analogues: Slow skin cell growth and can help reduce plaques (e.g., calcipotriene, calcitriol).
Retinoids: Derived from vitamin A, they reduce skin cell turnover and inflammation (e.g., tazarotene).
Calcineurin Inhibitors: Effective for sensitive areas, such as the face and folds of skin (e.g., tacrolimus, pimecrolimus).
Coal Tar: Slows skin cell growth and reduces scaling, itching, and inflammation.
Salicylic Acid: A keratolytic that helps remove scales, often used in combination with other therapies.
2. Phototherapy (Light Therapy)
Phototherapy is used for moderate to severe psoriasis, especially when topical treatments are ineffective.

UVB Phototherapy: Exposure to ultraviolet B (UVB) light slows the rapid skin cell turnover in psoriasis.
PUVA (Psoralen and UVA): Combines a drug called psoralen with UVA light. It’s typically used for severe cases.
Excimer Laser: Targets specific areas with a focused beam of UVB light, often used for smaller, localized lesions.
3. Systemic Treatments (Oral or Injectable Medications)
These are used for moderate to severe psoriasis or for cases that have not responded to topical treatments or phototherapy. Systemic treatments affect the whole body, so they come with a greater risk of side effects.

Methotrexate: Affects immune cell activity, helping reduce inflammation and cell turnover.
Cyclosporine: Suppresses the immune system, quickly reducing symptoms, but is usually for short-term use.
Oral Retinoids: Such as acitretin, help reduce skin cell production.
Apremilast: A phosphodiesterase-4 (PDE4) inhibitor that reduces inflammation by affecting specific immune pathways.
4. Biologic Therapies
Biologics are a newer class of systemic drugs that target specific parts of the immune system. These are usually injected or infused and are used for moderate to severe cases, particularly when other treatments have failed.

TNF-alpha Inhibitors: Target tumor necrosis factor-alpha, a cytokine involved in inflammation (e.g., adalimumab, etanercept, infliximab).
IL-12 and IL-23 Inhibitors: Target interleukin-12 and interleukin-23, which contribute to the inflammation process (e.g., ustekinumab).
IL-17 Inhibitors: Target interleukin-17, which is involved in the immune response (e.g., secukinumab, ixekizumab).
IL-23 Inhibitors: Block the action of interleukin-23 to reduce inflammation (e.g., guselkumab, tildrakizumab).

Question 36

benzodiazepines indicated to use as premedication before surgery?

Answer 36

Midazolam:

Common Choice: Midazolam is widely preferred because it has a rapid onset and a short duration of action, making it ideal for procedures where quick recovery from sedation is needed.
Uses: Provides sedation, anxiolysis, and amnesia, which helps to relax patients before surgery.
Administration: Can be given orally, intramuscularly, or intravenously.
Lorazepam:

Intermediate Duration: Lorazepam has a longer duration than midazolam but is still used preoperatively for patients who need a longer-lasting sedative effect.
Uses: Provides anxiolysis and amnesia.
Administration: Usually given orally or intravenously.
Diazepam:

Longer-Lasting Effects: Diazepam has a longer half-life, so it’s used less commonly for short procedures but can be effective in patients who require longer-lasting anxiolytic effects.
Administration: Typically given orally or intravenously.
Alprazolam:

Short-Term Sedation: Although less common in surgical settings, alprazolam may be used preoperatively for its anxiolytic effects.
Administration: Generally given orally.

Question 37

WHat interactions to benzodiazepines have?

Answer 37

Further notes on benzodiazepines and their interactions with other drugs:

Clozapine – serious adverse events reported with concomitant use of benzodiazepines and clozapine
Anti-Parkinson’s – benzodiazepines possibly antagonise effects of co-beneldopa and co-careldopa
Olanzapine – increased risk of hypotension, bradycardia and respiratory depression when parenteral benzodiazepines given with intramuscular olanzapine
Antihypertensive – enhanced hypotensive effects
Antidepressants – increased sedative effects