WEEK 14 OSPAP Programme Commonly prescribed medications Summary and prescribing advice Part 1

Slide 1 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Aciclovir

• What is it? – Anti-viral – Others in class – Famciclovir, Valaciclovir • Indication – Herpes simplex infections (eye, mouth, lips, genitals) – In individuals with good immune function, mild infection of the eye and lips (cold sores) can be treated topically – Primary or recurrent genital herpes simplex is treated orally – Varicella-zoster infections (chicken pox) – treat orally in immunocompromised patients or those with severe infection – start within 24 hours of onset of rash may reduce duration and severity of symptoms – Herpes-zoster infections (shingles) – systemic antiviral treatment can reduce the severity and duration of pain and complications – should be started within 72 hours and continued for 7-10 days • Interactions – see BNF • Side effects – GI, CNS, rash • Dose – herpes simplex treatment – 200mg 5 times daily for 5 days • Varicella and herpes zoster treatment – 800mg 5 times daily for 7 days

Slide 2 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Alendronic acid

• Bisphosphonate – adsorbed onto hydroxyapatite crystals in bone, slowing both their rate of growth and dissolution, and therefore reducing the rate of bone turnover. • Other drugs in class – Disodium etidronate – Risedronate – Others see BNF • Indication – Prophylaxis (long term or repeated steroid use) and treatment of osteoporosis (confirmed by DEXA scanning) • Interactions – Chelation – food/other drugs – Treatment should be accompanied with calcium/vitamin D supplementation • Side effects – Osteonecrosis of the jaw (rare but severe) – Dentists should be aware of treatment – Oesophageal reactions • Oesophagitis, oesophageal ulcers, oesophageal stricture etc • Dose – Daily vs Weekly • Counselling – important

Slide 3 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Alendronic acid – case studies

• A 85 year old women prescribed alendronic acid 70mg once per week for prophylaxis of osteoporosis as is on long term steroid treatment (prednisolone 7.5mg daily) • Admitted to hospital as general deterioration of heath/ability to cope at home • Some dysphasia, develops severe mouth ulcers • ? Cause

Slide 4 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Alendronic acid – case studies

• A 35 year old man on alendronic acid for prophylaxis of osteoporosis as requires long term treatment with steroids, requires dental treatment. • Develops osteonecrosis of jaw, some of which has to be removed as a result

Slide 5 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Alfacalcidol

• Vitamin D deficiency can be caused by intestinal malabsorption or chronic liver disease • Patients may develop hypercalceamia • CKD stage 4 and 5 should be prescribed alfacalcidol rather than colecalciferol. This is because vitamin D requires hydroxylation by the kidney to its active form, therefore the hydroxylated derivatives such as alfacalcidol should be prescribed • Vitamin D deficiency due to lack of exposure to sunlight or lack in diet in people with normal renal function or stage 1,2,3 CKD is treated with colecalciferol

Slide 6 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Alfuzosin

• Alpha-blocker (others in this class: doxazosin, indoramin, prazosin, tamsulosin, terazosin) • Urinary retention • Relax smooth muscle in benign prostatic hyperplasia producing an increase in urinary flow and an improvement in obstructive symptoms • Since selective alpha-blockers reduce blood pressure patients receiving antihypertensive treatment may require a dosage reduction

Slide 7 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Allopurinol

• Long term control of gout • The formation of uric acid from purines may be reduced with the xanthine-oxidase inhibitor allopurinol • Treatment should be continued indefinitely to prevent further attacks by correcting the hyperuriceamia • Should NEVER be started during an attack, usually started 2-3 weeks after the attack has settled • Interactions – See BNF • Dose – maintenance (100mg-300mg daily) • Side effects – Rashes – withdraw therapy, if rash mild re-introduce cautiously but discontinue immediately if re-occurs

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Slide 10 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amiodarone

• Amiodarone is used in the treatment of arrhythmias • Should only be initiated under hospital or specialist supervision • Very long half-life (extending to several weeks) • Many weeks or months are required to achieve steady state plasma- amiodarone concentration • This is important when considering drug interactions • Most patients develop corneal microdeposits (reversible on withdrawal of treatment) • Phototoxic reactions, patients should be advised to shield the skin from light during treatment and for several months afterwards • Amiodarone contains iodine and can cause disorders of thyroid function (TFT tests during treatment) –hepatotoxic response –raised transaminases • Pneumonitis should be suspected if SOB develops • Hepatoxicity (LFTs during treatment)

Slide 11 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amiodarone

• Very toxic in overdose (fatalities) • Needs loading dose due to long half life • 200mg tds for 1 week, reduced to 200mg bd for a further week, maintenance 200mg daily • Side effects are dose and duration of treatment related – reduce dose reduce incidence of side effects

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Slide 14 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amitriptylline

• Tricyclic antidepressant

• Those with sedative properties include amitriptyline, clomipramine, dosulepin, doxepin, trazodone

• Less sedative – imipramine, lofepramine and nortriptyline

• Side-effects – cardiovascular (arrhythmias and heart block) – anti-muscarinic (drowsiness, dry mouth, blurred vision (very rarely precipitation of angle-closure glaucoma), constipation, urinary retention)

• Overdosage – limited quantities of tricyclic antidepressants should be prescribed at any one time because their cardiovascular effects are dangerous in overdosage – dosulepin and amitriptyline is associated with high rate of fatality

Slide 15 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amitriptyline

• Amitriptyline is now rarely used an an antidepressant, now more likely to be used for neuropathic pain at lower dosages 10mg - 50mg daily

Slide 16 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amlodipine

• Calcium-channel blockers interfere with inward displacement of calcium ions • They influence the myocardial cells, the cells within the specialised conducting system of the heart, and the cells of vascular smooth muscle • Myocardial contractility nay be reduced, the formation and propagation of electrical impulses within the heart may be depressed, and coronary or systemic vascular tone may be diminished • Verapamil and Diltiazem vs dihydropyridine calcium channel blockers (amlodipine, felodipine, isradipine, lercanidipine, nicardipine, nifedipine) • Verapamil (negative inotropic effect) and diltiazem should be avoided in heart failure because they may further depress cardiac function and cause clinically significant deterioration. Verapamil should NOT be used with beta-blockers and diltiazem used with care

Slide 17 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amlodipine

• Dihydropyridine calcium channel blockers (ie amlodipine) relax smooth muscle and dilate coronary and peripheral arteries. • More influence on the vessels and less on the myocardium • Don’t have anti-arrhythmic activity • Different durations of action • Licensed for hypertension and or prophylaxis of angina • Grapefruit juice increases plasma concentations of felodipine, isradipine, lacidipine, lercanidipine, nicardipine, nifedipine, nimodipine, nisoldipine and verapamil • Ankle swelling common with amlodipine 10mg

Slide 18 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Amoxicillin

• Broad spectrum antibiotic • Always check allergy • Macropapular rashes commonly occur with amoxicillin but are not usually related to true penicillin allergy

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Slide 20 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Aspirin

• Not now used as an analgesic • Prophylaxis of cerebrovascular disease or myocardial infarction (secondary prevention) • 75mg daily • ? Control BP before initiation • If patient is at high risk of gastro-intestinal bleed, a proton pump inhibitor can be added

Slide 21 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Atenolol

• Beta-adrenoceptor blocking drugs, act in the heart, peripheral vasculature, bronchi, pancreas and liver • Beta-blockers should be avoided in patients with a history of asthma or bronchospasm • Some are cardioselective but not cardiospecific, have less effect on airways resistance but are not free of this side effect • Assoicated with fatigue, coldness of the extremities and sleep disturbances with nightmares • Can be used for a variety of indications – Hypertension Arrhythmias – Angina Heart failure – Post MI

Slide 22 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Azathioprine

• Immunosuppressant • DMARD • Used in transplant recipients and in a number of auto-immune conditions • Blood tests and monitoring for sings of myelosuppression are essential (FBC) • The enzyme TPMT metabolises azathioprine • Risk of myelosuppression increased in people with low activity

Slide 23 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Beclomethasone

• Inhaled corticosteroid • Now changed to CFC – note not equipotent • Prescribed as per BTS guidelines for asthmatic patients, some use in COPD (unlicensed) • Can induce adrenal suppression at high doses – steroid card (doses above 2mg) • Bone mineral density can be reduced • Growth retardation in children • Oral thrush

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Slide 25 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Bendroflumethiazide

• Thiazide diuretic • Inhibit sodium re-absorption in the distal convoluted tubule • A low dose i.e. 2.5mg produces a maximal blood pressure lowering effect with little biochemical disturbance • Higher doses cause more marked disturbance in plasma potassium, sodium, uric acid, glucose and lipids with little advantage for blood pressure control • Now removed from hypertension guidelines as no good evidence for outcomes (evidence that does exist is for trials which used 10mg)

Slide 26 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Bupropion

• Smoking cessation aid • Contra-indicated in patients with history of seizure, alcoholism and in patients at high risk of seizures or on other medications that can lower the seizure threshold

Slide 27 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Candesartan

• Angiotensin II inhibitor

Slide 28 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Candesartan

• Others in class – eprosartan, irbesartan, losartan, olmesartan, telmesartan, valsartan • Used second line to ACE inhibitors • Unlike ACE they do not inhibit the breakdown of bradykinin and therefore are unlikely to cause a dry cough • All licensed to treat hypertension – some have other indications

Slide 29 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Citalopram

Slide 30 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Citalopram

• Selective serotonin reuptake inhibitor • Others in the class – escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline • SSRIs are less sedative and have fewer antimuscarinic and cardiovascular effects than TCAs • GI side effects • Some reports of suicidal behaviour – particularly in young people • Not ‘addictive’ but there are withdrawal effects

Slide 31 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Citalopram and QT interval

• Citalopram and escitalopram are associated with dose- dependent QT interval prolongation and should not be used in those with: congenital long QT syndrome; known pre-existing QT interval prolongation; or in combination with other medicines that prolong the QT interval. ECG measurements should be considered for patients with cardiac disease, and electrolyte disturbances should be corrected before starting treatment. For citalopram, new restrictions on the maximum daily doses now apply: 40 mg for adults; 20 mg for patients older than 65 years; and 20 mg for those with hepatic impairment.

Slide 32 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Clopidogrel

• Anti-platelet • Licensed for secondary prevention IHD • Second line (except remember stroke secondary prevention) • Aspirin and clopidogrel after stent, non-STEMI (1 year) • Interacts with omeprazole/esomeprazole

Slide 33 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Codeine phosphate

• Weak opiate • Opiate side effects, drowsiness, constipation • Tolerance • Pro-drug • 8/500 co-codamol sub-therapeutic dose

Slide 34 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Diazepam

• Benzodiazepine • Licensed for short term use in anxiety or insomnia • Highly additive • Used in alcohol withdrawal • Status epilepticus

Slide 35 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Diclofenac

• Non-steroidal anti inflammatory drug • Main side effects are GI and CVS • Risks and benefits must be carefully balanced • Precautions can be put in place ie PPI cover

Slide 36 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Diclofenac

• MHRA guidance • Available data indicate that the cardiovascular risk with diclofenac is similar to that of the selective COX-2 inhibitors. Consistent with COX-2 inhibitors, diclofenac is now contraindicated in those with: ischaemic heart disease; peripheral arterial disease; cerebrovascular disease; or established congestive heart failure (New York Heart Association [NYHA] classification II–IV). The treatment advice applies to systemic formulations (ie, tablets, capsules, suppositories, and injection available both on prescription and via a pharmacy, P); it does not apply to topical (ie, gel or cream) formulations of diclofenac

Slide 37 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Digoxin

• Cardiac glycoside • Used in heart failure and arrhythmias • Long half life • Side effects are usually associated with excessive dosage – anorexia, nausea, vomiting, diarrhoea, abdominal pain, headache, confusion etc • Narrow therapeutic index • Regular monitoring of plasma concentration not needed unless toxicity suspected • Care with dosages • Hypokalaemia predisposes to toxicity

Slide 38 of 39 MPHM14 OSPAP Commonly prescribed drugs WEEK 14 Digoxin

• Dosage dependant on age/lean body weight and renal function • Sampling for serum levels should be taken at least 6 hours after the last dose • Therapeutic range 0.5-1microgram/L • Other monitoring: heart rate, BP, ECG, K+

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