Herbal Medicine

Penny Franklin MA Complementary Health Studies Senior Lecturer Non medical prescribing University of Plymouth May 2005

Intended presentation outcomes

 Discuss the significance of Complementary and alternative medicine for conventional prescribing  Highlight the difficulties involved in obtaining reliable information on this topic  Discuss significant drug interactions and cautions that relate to different patient groups

History

        Complementary and alternative medicine (CAM) Herbal medicine at least 5,000 years old CAM interest grown over past two decades Over 31 million visits to CAM practitioners 1998 (Thomas et al, 2001) One in five Britons seeks complementary or alternative therapy.

Perceived to be ‘safe’ Research lagging behind Health care professionals are thought to know

What is CAM?

 Complementary and alternative medicine. The treatment of disease using methods other than recognised/conventional medicine.  Use of homeopathic, herbal, aromatherapy and over the counter vitamin supplements to treat conditions  Often not adequately clinically trialled  Might not have a product licence

Homeopathic and Herbal medicine

        Homeopathy: Homeos (Similar) Pathos (disease) Like cures like – remedy mimics symptoms The greater the dilution – the greater the therapeutic effect (serial dilution)- hardly any or no trace of active ingredient Manufacture controlled by Medicines Act 1968 Medical claims cannot be made for remedies However, leaflets can be displayed nearby Medical homeopaths (medically qualified and regulated by GMC) Non Medical homeopaths (regulated by different bodies/Fellowship of homeopaths etc

Effects on patients

 Limited evidence with regard to adverse drug reactions  Little evidence with regards to drug interactions

Herbalism

 National Institute of Medical Herbalists 1864 (professional body)  Phytotherapy-the science of herbalism

Herbal medicines

 Plant derived medicines at pharmacological doses where effects can be measured  Symptom based approach to diagnosis

Commonly used herbal medicines

 Glucosamine (not strictly herbal)- For relief of joint pain (side effects:mild GI symptoms, rash, drowsiness, headache and insomnia  May alter glucose sensitivity  Caution if pregnant or breastfeeding or if allergic to shell fish

Saw Palmetto

 Urogenital conditions – Benign prostatic hyperplasia  Side effects: - dizziness, and GI disturbance  Rare,- mild puritis, headache and hypertension  ? Erectile dysfuntion (similar to placebo)  Drug interactions ? Hormonal therapies (Contraception and HRT)  Cautions: Pregnancy and breastfeeding, sex hormone dependent cancers

Valerian

 Insomnia  Side effects: headache, drowsiness, (sedation) GI symptoms, rarely nervousness and excitability  ? Cardiac disturbances rarely on sudden withdrawal (not confirmed)  Precautions: Pregnancy and breastfeeding, before driving or operating heavy machinery,  Not to be taken if known hypersensitivity  Can cause dependency

St John’s Wort

 Mild depression –  Caution (Liver enzyme inducer (anti epileptics)( theophylline )(the Pill) (SSRI’s), ( wafarin)

Echinacea

      Prevention of upper respiratory tract infections Side effects: Nausea, dizziness, shortness of breath, burning and numbing sensation on tongue, dermatitis, hepatitis, puritus and hepatoxicity Drug interactions: Other hepatotoxic drugs e.g anabolic steroids, amiodarone, ketoconazole and methotrexate also immunosuppressants (might decrease effect) Cautions: asthma, atopy or allergy, hypersensitivity to sunflowers, liver dysfunction, TB, diabetes, HIV, MS, SLE and other autoimmune diseases Pregnancy and breastfeeding Do not take continuously for more than eight weeks

Regulation of herbal medicines

 Licensed: Marketing authorisation (product license) issued by Medicines and Health Care products Regulatory Agency (MHRA)  Have to meet safety, quality and efficacy standards similar to conventional drugs  Unlicensed: Exempt from licensing requirements (Section 12 of Medicines act 1968)

Section 12 Medicines Act 1968

     Section 12 (1) person can make, sell and supply herbal remedy as part of business provided remedy is manufactured on the premesis and supplied as the consequence of a consultation between patient and herbalist 12(2) allows manufacture and supply where Process of manufacture consists of drying, crushing or comminuting Remedy sold without any written recommendation as to its use Remedy sold under a designation which only specifies the plant and the process and does not apply any other name to the remedy

Statutory regulation

 Moves afoot to regulate industry

House of Lords Select Committee 2000

 Tougher regulation  More rigorous testing  Greater supervision of practice  Only those with a statutory regulation or powerful self regulation should be available on NHS  Only by referral from GP.

Safety and Regulation.

 “We are concerned about the safety implications of an unregulated herbal sector and we urge that all legislative avenues be explored to ensure better control of this unregulated sector in the interests of public health.”

Safety

  Lack of data ‘Natural’ does not always mean safe e.g digitalis  Kava Kava hepatotoxicity

Safety Issues

 Remember herbal remedies are medicines  Report adverse reactions to doctor or pharmacist  May interact with other medicines  Natural does not mean safe

Duty of Care when prescribing

 To facilitate full and informed consent  To do no harm  Negligence – Proven breach of duty of care and harm to patient

When prescribing

 Always ask the patient what else they are taking  Including Over the Counter medication and herbal medicines  Consider potential drug interactions  BNF (2005) and Stockley (2002)

Alert

 Patients taking drugs with a narrow theraputic index e.g wafarin or a drug therapy which is considered critical ( e.g insulin) should avoid using complementary medicines  Women who are pregnant or breastfeeding should avoid complementary medicines

Problems

 Poor manufacturing process  Adulteration to include toxic substances and conventional drugs  Misidentification of herbs  Substitution of herbs  Varying strengths of preparations  Incomplete labelling  Incorrect dosage and instructions

Reporting

 To the MHRA using yellow card reporting  Important for all drugs especially those less well known.

References

     http://www.mcs.gov.uk/ourwork/licensingmeds/herbalsafety Stockley IH (2002) Drug interactions. 6 th Pharmaceutical Press; 2002 edition. London: Thomas, K et al., Use and expenditure on complementary therapies in England: a population based survey. Complementary Therapies in Medicine 2001; 9(1): 2-11 Zollman C, Vickers A. ABC of complementary medicine: what is complementary medicine? BMJ 1999; 319: 693-696 UKMI Complementary Medicines Summaries December 2002