1 / 77

Prescription-Only Medicines now Accessible to Podiatrists The Science Behind Them

Prescription-Only Medicines now Accessible to Podiatrists The Science Behind Them. Dr Jean Mooney PhD, FChS, FCPodS, FCPodMed, FHEA. Pods and POMs: History. ~1980 Statutory Instrument gave access to 4 injectable plain local anaesthetic solutions ~1996 Further SI gave access to

savannah
Download Presentation

Prescription-Only Medicines now Accessible to Podiatrists The Science Behind Them

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Prescription-Only Medicinesnow Accessible to PodiatristsThe Science Behind Them Dr Jean Mooney PhD, FChS, FCPodS, FCPodMed, FHEA

  2. Pods and POMs: History • ~1980 Statutory Instrument gave access to • 4 injectable plain local anaesthetic solutions • ~1996 Further SI gave access to • 2 adrenalinised local anaesthetics • Topical anti-fungal agents • Topical 1% corticosteroid • 3-day course Ibuprofen, 200mg tds

  3. Patient Group Directions • Legal framework (August 2000) • Allowed Podiatrists to supply and administer specified medicines to patients who are designated as within a group as defined by the PGD • e.g: Diabetics with soft tissue or bone infections • POMs supplied directly to a patient without the need for a separate prescription from a prescriber. • PGD allows access to POMs for specific types of patient presenting with a specific need: it is NOT a form of prescribing • PGD does not require the podiatrist to have any additional qualification • Employing organisation must ensure that only fully competent, trained health care professionals use PGDs.

  4. Supplementary Prescribing (2005) • Voluntary prescribing partnership between IP and SP • Implements an agreed patient-specific clinical management plan (CMP) • CMP agreed between • IP: doctor • SP: podiatrist • Patient • Podiatrist must undergo training (~6/12) to become SPs • HPC-Register annotated • Allows them to prescribe or adapt dosage of POMs specified within the CMP without recourse back to IP

  5. Pods and POMs: 17.11.2006 • SI extended access to the list of POMs that can be administered, sold and supplied to patients by Podiatrists • Schedule 5, Articles 4(2) and 4(4) amended Part I and III of Schedule 5 to the Prescription Only Medicines (Human Use) Order 1997 • Also regularised access to some Pharmacy medicines (P) for topical application e.g.: • 1% Griseofulvin • 1% Terbinafine 2006

  6. Adrenaline 2 more plain LA solutions Levobupivacaine Ropivacaine 4 Anti-microbial agents Amoxicillin Erythromycin Flucloxacillin Silver Sulfadiazine Anti-inflammatory Methylprednisolone Additional POMs from 17.11.06

  7. Further amendments allowed additional access to other medicines from 10.03.2011 • Ibuprofen (400mg) • Codeine phosphate • Co-codamol • Co-dydramol (10/500) • Pre-mix injectable solutions • E.g.: Depomedrone (Pre-mixed Lidocaine and Methylprednisolone)

  8. Recommendations • Continue to use all means of access to POMs • e.g.: PGDs • Train as a Supplementary Prescriber • Not easy for those in private practice • Gain HPC annotation • POMs • LA

  9. College of Podiatrists Recommendations Codeine, Co-codamol and Co-dydramol • Indicated for short term treatment of acute / moderate pain unrelieved by paracetamol, ibuprofen or aspirin • Limited to a maximum of 3 days prior to direct patient review • even though the pack size may exceed that dose level • Essential that all Medicines are correctly labelled and supplied with an explanatory leaflet that clearly states • Dosage • Side effects (e.g.: constipation) • Possibility of addiction or habituation

  10. Pharmacodynamics Adverse Drug Reactions

  11. Pharmacodynamics • The effects of the drug on the body • desired and undesired effects of the drug on body systems • Intended effects • Modes of action / drug-receptor interaction • Doses and maximum safe doses • Undesired / unwanted / unexpected effects = Adverse drug reactions (ADRs)

  12. Classes of Adverse Drug Reaction (1) • Type A: • Addative effects • Dose related • Predictable effect • Not usually severe • Management: • Dose modification

  13. Classes of Adverse Drug Reaction (2) • Type B • Bizarre, unexpected effect • Unpredictable • Immunological basis • Rare: can be life threatening • Management: • Immediate withdrawal of drug • Counter treatment, where possible • Avoid all future exposure to the drug

  14. Comparison: Type A and Type B ADRS

  15. Other Types of Adverse Drug Reaction • Type C • Chronic administration • Habituation; tolerance; dependence • Type D • Delayed effects • Drug does not ‘kick in’ when expected • Type E • Exclusion • Effects of drug withdrawal • Type F • Failure of therapy • Often due to drug interactions

  16. Frequency of ADR, by Class of Drug

  17. ADR-Risk Patients • Elderly • Very young • Renal disease • Liver disease • Genetic predisposition ADRs attributed to Celecoxib (COX2 inhibitor) in 6/12 period

  18. ADR avoidance • Use prescribed medications only when necessary • In the lowest dose, to achieve required effect • For the shortest time, to maintain the required effect • Patients should be warned of the possibility of ADR occurring • Package advice leaflet • BNF Yellow card system • Report all suspected ADRs

  19. Pharmacokinetics Drug Interactions

  20. Pharmacokinetics • The effects of the body on the drug • How the body deals with the drug • What the body does to the drug • Absorption • Metabolism • Excretion • Drug interactions

  21. Drug Interactions (DIs) • Effect or action occurring in the body • Beneficial / desired • Adverse / unwanted • Due to taking two or more drugs, or one drug+ • OTC medicines • Vitamin and mineral supplements • Medicinal herbs • Foods • Does not occur when taking either alone • DIs usually inadvertent, e.g.: • POM + OTC • Drugs supplied by more than one prescriber • The more drugs that are taken, the more likely that DI will occur • Often under-reported as they mimic exaggerated action of drug

  22. Drug Interactions • Desired effects: potentiating effect of drugs used in combination • e.g.: codeine combined with paracetamol gives greater pain relief • Undesired effects: one drug mitigates the effect of another • e.g.: Erythromycin reduces the effectiveness of oral contraceptives • Most DIs arise due to effects on Cytochrome P450 enzymesystem • absorption by small intestine • metabolism to non-active substances by liver • (non-active substances excreted via the kidney: may still carry some drug effect) • DIs also occur when drug constituents interact with e.g.: foods, antacids, vitamin, mineral or herbal supplements • e.g.: Antacids can bind with antibiotics preventing blood uptake • It is essential that the name and dosage of all medications (including OTCs) are identified before supplying a POM to a patient • Full medical history

  23. Antibiotics

  24. Antibiotics (ABx) • Substances that kill or inhibit a range of MOs • Any MO-derived substance that antagonizes growth of another MO in high dilution • Dose: usually minimum 5-7 days • to ensure full MO kill • wound swab BEFORE starting ABx • review patient after 3 days to check response to AB treatment • Classified • By manufacture • natural, semi-synthetic or synthetic analogues of natural compounds • Spectrum of biological effect • Bactericidal / Bacteriostatic • Susceptibility of a range of MOs to ABx effect • Broad / Medium / Narrow spectrum

  25. AmoxicillinFlucloxacillinErythromycinSilver Sulfadiazine Available to HPC POM-annotated Podiatrists since Nov 2006

  26. Beta-lactam penicillin-type antibiotic with moderate-spectrum of activity Bacteriolytic Inhibits synthesis of G+ve and G-ve bacterial cell walls Good absorption with oral administration MO resistance is common MOs produce beta-lactamase and degrade amoxicillin Often formulated in combination with clavulanic acid (Co-amoxiclav / Augmentin) to overcome MO resistance Amoxicillin

  27. Dose: 250mg / 500mg tds Uses Skin infections (No longer recommended for prevention of bacterial endocarditis) Side effects (ADRs) D+V Non allergic rashes Affects 3-10% of children Anaphylaxis Amoxicillin Contd:

  28. Flucloxacillin • Beta-lactam penicillin-type antibiotic with narrow spectrum of activity • Inhibits synthesis of bacterial cell walls • Used to treat infections caused by susceptible G+ve bacteria • Active against beta-lactamase MOs, such as Staph aureus • Not effective against G-ve organisms or non-beta lactamase producing G+ves • Ineffective against MRSA • MO Resistance

  29. Flucloxacillin Contd. • Dose • 250-500mg qds • Uses • Skin infections • Surgical prophylaxis • Cellulitis • May be combined with ampicillin (Co-fluampicil) if Strep pyogenes suspected • ADRs include • D+V, superinfection (candidiasis), allergy • Avoid use in patients with renal or hepatic impairment

  30. Erythromycin • Bactericidal macrolide antibiotic • Slightly wider antimicrobial spectrum than penicillins • Unknown mechanism of activity • Taken up by macrophages so concentrates in area of infection • Often used in subjects with penicillin allergy • Indicated for skin infections • Metabolised in the liver

  31. Erythromycin Contd. • Dose • 250mg qds • Non acid-stable (give after meals) • Clarythromycin is acid-stable • ADRS include • D+V, nausea and abdo cramps • Cardiac arrhythmias and deafness • Allergies • To be avoided in infancy, pregnancy and lactation • Not used in conjunction with many drugs • e.g.: Warfarin, OCs, corticosteroids, simvastatin, anti-migraine drugs, verapamil, terfenadine, theophilline, clindamycin

  32. Silver Sulfadiazine • Topical agent • 1% cream • Sulfonamide and Silver • Antibacterial: broad-spectrum activity in chronic wounds • G+ve and G-ve bacteria (including Pseudomonas aeruginosa) • Some yeasts and fungi • Poor penetration on normal skin • Up to 1% show hypersensitivity reaction, e.g.: • Rashes; erythema multiforme • Skin discolouration (argyria) • Avoid in late pregnancy / infancy • Avoid in patients with G6PD deficiency • May increase wound healing times • Not recommended by Cochrane review

  33. LET’S See you again in 15 mins

  34. Pain control Analgesia Anaesthesia

  35. Analgesics • Analgesic = painkiller • an = without; algos = pain • NB: Anaesthetics = without sensation • Act at PNS and / or CNS membrane receptors • Include  • Paracetamol (acetaminophen in US), • NSAIDs, e.g.: Salicylates (aspirin), Ibuprofen • Opioids, including Morphine and Codeine • CoP advice: • Max administration = 3 days, then direct patient review • Analgesic choice is determined by • Severity of pain • Pain type, e.g.: neuropathic pain is more responsive to tricyclic antidepressants and anticonvulsants (e.g.: gaba-pentin)

  36. Codeine phosphate • Opiate drug • Weak to mid-range opioid • Makes up 3% of opium • CSN and PNS action • Actions • Analgesic, anti-tussive, anti-diarrhoeal • Side effects (especially in overdose) • Gut immobility • Respiratory suppression • Tolerance, habituation, addiction, coma, death • Codeine is metabolised to morphine • 5% show rapid metabolism to morphine ‘High’ • Avoid use during lactation

  37. Codeine contd. • Unwanted side effects include • Euphoria, itching, nausea, vomiting, drowsiness, orthostatic hypotension, urinary retention, depression, constipation, and paradoxical coughing • Hives and rashes due to allergic reaction • Long-term administration causes erectile dysfunction and hypogonadism (especially in white males) • Sugar cravings • Induces hypoglycaemia (the ‘munchies’) • Was once used to control diabetes, as was morphine

  38. Co-dydramol • Compound analgesic • Dihydro-codeine tartrate 7.5 / 10 / 20 / 30mg • + Paracetamol 500mg • Used to relieve moderate pain • Side effects • Allergic reactions - urticaria, breathing difficulty, increased sweating, facial flushing, mouth ulcers. • Abdominal pain • GIT upsets: abdominal pain, nausea, heartburn, constipation, loss of appetite, dry mouth, • Blood problems - anaemia, nose bleeds, increased risk of infection, bruising.

  39. Co-dydramol Side Effects Contd • UT upsets - pain or difficulty in passing urine. • Nervous system - confusion, drowsiness, dizziness, mood changes, depression, hallucinations, restlessness, excitation, fits, painful eyes, headache, sleeping problems, • Tolerance or dependence. • Eyes - blurred or double vision, extremely small pupils. • Other - trembling, tiredness. weakness, malaise, low body temperature, muscle stiffness, changes in libido.

  40. Co-Codamol • Compound analgesic • Codeine phosphate 8 / 12.8 / 15 / 30mg • + Paracetamol 500 / 1000mg • For the relief of mild – moderate pain, • where paracetamol alone, or NSAIDS (aspirin, ibuprofen, naproxen) does not control the pain

  41. Co-codamol Contd. • Side effects include • Allergic reactions: Shortness of breath Hypersensitivity, pruritis, Rashes, • CNS effects: Confusion, Loss of short term memory, Dizziness, Fainting, Drowsiness, Sedation, Euphoria, dysphoria, addiction. • Blood changes: bleeding gums, easy bruising • GIT effects: Abdominal pain, Nausea / vomiting, Constipation • Others: Dry mouth;

  42. Paracetamol (Acetaminophen) • OTC analgesic and antipyretic • Relief of minor aches and pains • COX2 inhibitor • COX + arachidonic acid  prostaglandin • Reduces Prostaglandin E2  lowers temperature • Modulates endogenous canabinoid system •  pain awareness reduced • Inhibits sodium channels in pain fibres • Constituent of many cold and ‘flu relief remedies • Does not cause gastric irritation • Does not have marked anti-platelet effect • Used in combination with opioid analgesics to control more severe pain, e.g.: post surgery

  43. Paracetamol contd. • Onset of analgesia is approximately 11 minutes after oral administration • Half-life = 1–4 hours. • Metabolised by liver • Recommend dose = 1g tds • 3g daily • 2g daily maximum for heavy drinkers • 325mg tds in USA • Acute overdose causes potentially fatal liver damage • First aid = activated charcoal • Paracetamol toxicity is foremost cause acute liver failure • Rare individuals develop irreversible liver damage at normal dose • Risk of overdose increased by alcohol consumption

  44. Local Anaesthetics • Lidocaine hydrochloride (Xylocaine) • Lidocaine hydrochloride + 1:200,000 adrenaline • Bupivacaine hydrochloride (Marcain) • Bupivacaine hydrochloride + 1:200,000 adrenaline • Mepivacaine (Scandonest) • Prilocaine (Citanest) • Levo-Bupivacaine (Chirocaine) • Ropivacaine (Naropin)

  45. LAs prevent generation of nerve impulses (action potentials) in pain fibres • Injected LA diffuses into nerve fibre • LA molecule blocks Na+channels in nerve fibre membrane • Nerve impulse cannot be generated • LA gradually diffuses out of the nerve fibre • Nerve function returns to normal • Impulse can be generated and propagated • LA taken up from site of injection into general circulation • LA metabolised in liver and excreted via kidney

  46. Onset of Action • Lidocaine hydrochloride = 5 mins • Bupivacaine hydrochloride = 20 mins • Mepivacaine = 10 mins • Prilocaine = 10 mins • Levo-Bupivacaine = 20 mins • Ropivacaine = 10-30 mins

  47. Duration of Action • Lidocaine = 1-2 hours • Lidocaine + 1:200,000 adrenaline = 2-4 hours • Bupivacaine = 6-8 hours • Bupivacaine + 1:200,000 adrenaline = 12-16 hours • Mepivacaine = 2-4 hours • Prilocaine = 2-4 hours • Levo-Bupivacaine = 5-15 hours • Up to 30 hours post-op analgesia • Ropivacaine = 4-8 hours • Up to 24 hours post-op analgesia

  48. Cautions • Do not inject adrenalinised solutions into the distal foot • Causes ischaemia • ‘Chemical tourniquet’ • Ischaemic effect persists for duration of anaesthesia • Avoid adrenalinised solutions in patients taking • Beta-blockers • MAOIs • Tri-cyclic anti-depressants

  49. Calculation (in mg) of total LA dose administered from drug labelled as % solution • Percentage Mass • 1% solution = 10mg of drug in 1ml • 2% solution = 20 mg of drug in 1ml • 3% solution = 30mg of drug in 1ml • THUS • 3.5ml of 1% soln delivers 35mg of drug • 8.3ml of 2% soln delivers 166mg of drug • 5.6ml of 3% soln delivers 168mg of drug

  50. Maximum safe doses 70Kg or >70Kg person • Lidocaine • 200mg (3mg / Kg) • 20ml of 1% OR 10ml of 2% soln • Bupivacaine / Levobupivacaine • 150mg (2mg / Kg) • 30ml of 0.5% OR 60ml of 0.25% soln • Mepivacaine OR Prilocaine • 400mg (6mg /Kg) • 13ml of 3% soln • Ropivacaine • ~250mg (4mg/Kg) • 50ml of 0.5% OR 33ml of 0.75% soln

More Related