Complementary Medicines & Recreational Stimulants/Hallucinogens – Comprehensive Study Notes

Acknowledgement of Country

Kaurna people acknowledged as traditional custodians of the land.
Respect paid to their past, present and ongoing cultural connection.

Learning Objectives (Complementary Medicines Section)

Define “complementary therapies” and distinguish from conventional medicine.
Focus on complementary medicines (CMs): usage, motivations, risks.
Explain pharmacokinetic (PK) and pharmacodynamic (PD) interactions with prescription drugs.
Recognise toxicity, allergic reactions, regulatory and consumer-behaviour issues.

What Are Complementary Therapies?

Broad umbrella: herbal medicines, vitamins, nutritional supplements, homeopathy, acupuncture, aromatherapy, Ayurvedic medicine, mind–body, manipulative, energy and biologically-based methods.
Therapeutic Goods Administration (TGA) working definition: non-prescription medicines with an established tradition of use, taken alongside “standard” medical treatments.
Alternative naming systems: “alternative medical systems”, “biologically-based therapies” etc.

Key Industry Facts (CMA Report $2024$ )

>75\% of Australians used at least one CM in previous $12$ months.
$\sim 7 \text{ out of } 10$ Australians overall; women aged $25 – 60$ , higher education predominance.
$\$6.2$ billion annual market (breakdown):
• Vitamin/ dietary $\$2.65$ b • Sports nutrition $\$1.2$ b • Herbal/traditional $\$0.63$ b • Weight loss $\$0.43$ b • Exports $\$1.2$ b (Australia #1 exporter to China, $\$1$ b).
Projected CAGR $2024–29$ : Vitamins $5.9\%$ , Sports nutrition $7.2\%$ , Herbal $5.4\%$ , Weight management $0.5\%$ .

Patterns of Use

>50\% fail to disclose CM use to GPs; $18\%$ withhold herbal-medicine use from any health professional.
Motivations: dissatisfaction with conventional care, mistrust of pharmaceuticals, autonomy, cultural alignment, ease of online access/telehealth.
Conditions targeted:
• $70\%$ general wellness • $21\%$ musculoskeletal • $18\%$ immunity • $13\%$ mental health • $9.5\%$ cardiovascular (SA $2004$ ).
• $65\%$ chronic illness overall (AU $2019$ ). Specific: mental health $29\%$ , cardiovascular $21\%$ , diabetes $11\%$ , cancer $7\%$ , autoimmune $3.5\%$ , etc.

Representative Complementary Medicines

Cranberry juice: historical urinary-tract infection remedy; limited efficacy; possible drug interactions.
Echinacea: assorted species/plant parts; weak evidence for shorter colds; allergy risk.
St John’s Wort: antidepressant-like (SSRI-like); major PK & PD interactions (see below).

Why CM Use Raises Concerns

Misconception of “natural = safe”.
Interaction potential → altered drug PK/PD, therapeutic failure, toxicity.
Adverse effects: overdose, allergic reactions.
Variable dosing & product heterogeneity (seasonal variation, substitutions, inconsistent actives).
Limited evidence for benefit in well-nourished people; exceptions: folate in pregnancy, malnourished cancer pts.

Regulation in Australia

TGA ensures quality/safety; does NOT conduct in-house efficacy testing.
Categories:
• AUST L (Listed): symptomatic relief/health maintenance, evidence may be traditional/weak. Manufacturer self-certifies evidence.
• AUST R (Registered): prescription or higher-risk CMs; require full evaluation incl. controlled clinical trials.
Advertising regulated by TGA code.
Gaps: Internet imports, bulk purchasing, unapproved medicines, homeopathy, variable overseas manufacture → adulterants (heavy metals, prescription drugs, toad venom) and contaminants.

Pharmacokinetic Interactions – exemplar: St John’s Wort (SJW)

Active: hypericin (plus hyperforin etc.).
Induces CYP $3A4$ , CYP $2C9$ , CYP $2C19$ → ↑ metabolism ↓ plasma levels of co-medications.
Clinical outcomes:
• Cyclosporin ↓ → transplant rejection.
• Digoxin ↓ → worsening heart failure.
• Oral contraceptives ↓ → contraceptive failure.

Pharmacodynamic Interactions – exemplar: SJW

Inhibits re-uptake transporters for serotonin, NA, dopamine, GABA, glutamate → additive with SSRIs/SNRIs.
Risk of Serotonin Syndrome: agitation, confusion, tremor, hyperthermia.

Toxicity & Poisonings

Hepatotoxicity (> $22\%$ of non-paracetamol DILI): valerian, CM-paracetamol combos.
Nephrotoxicity: aristolochic acid → interstitial nephropathy, urothelial cancers; often from herb substitution.
Unintentional poisonings: oral aloe vera (laxative); mis-identified mushrooms (psilocybin vs amatoxin).

Adverse Reactions

Predictable: pharmacological (HTN, bleeding, etc.).
Unpredictable: substitution, adulteration (e.g. sildenafil in “herbal” erection pills), contamination (microbial, gluten, cross-equipment).
Allergies: royal jelly in bee-allergic pts; glucosamine (shellfish); echinacea (daisy family); gluten in fillers.

Why Pharmacology Cares – Natural Products as Drug Templates

Willow bark → aspirin (fever/pain)
Foxglove → digoxin (cardiac arrhythmia)
Rosy periwinkle → vincristine (leukaemia)
Pacific yew → taxol (ovarian cancer)
Opium poppy → morphine (analgesia)
Snakeroot → reserpine (hypertension)

Recreational Drugs: Stimulants & Designer Drugs

Lecture Objectives (Stimulant/Hallucinogen Section)

Recognise prevalence of recreational drug use.
Contrast natural vs synthetic stimulants & hallucinogens; identify targets, desired & adverse effects.

Epidemiology (AIHW $2019$ , > $14$ yrs)

Daily tobacco $11\%$ , cocaine $4.2\%$ , ecstasy $3\%$ , hallucinogens $1.6\%$ , meth/amphetamine $1.3\%$ , heroin <0.1\%.

Stimulant Classes & Examples

Natural: nicotine, caffeine, cocaine, khat.
Synthetic: amphetamine, methamphetamine, MDMA, designer analogues.

Cocaine

Forms: HCl salt (powder, snorted); base “crack” (smoked/injected).
MoA: blocks DAT & NET (dopamine/noradrenaline transporters).
Duration $15$ min – $1$ h.
Wanted: intense euphoria (“orgasmic”), ↑ energy/confidence.
Unwanted: addiction, paranoia, depression, cardiovascular events.

Amphetamine & Methamphetamine

Similar to endogenous catecholamines → taken up by transporters, enter vesicles via VMAT, displace monoamines; also weak MAO inhibition.
Sympathomimetic effects: euphoria, ↓ fatigue, anorexia (tolerance develops), alertness.
Adverse: addiction, anxiety, paranoia, hypertension.
Meth routes: powder “speed”, pills, crystal “ice”.
Societal response: National Ice Action Strategy ( $\$60$ M; prevent, treat, harm-reduce).

Designer Stimulants

Structural tweaks on amphetamine scaffold; produced in “garage labs”.
Unpredictable potency & toxicity; poly-drug tablets (combinations not $100\%$ pure).

MDMA (Ecstasy)

Designer amphetamine derivative.
Desired: intense excitement, empathy, energy.
Adverse: hyperthermia, tachycardia, HTN, seizures, coma, death; addiction possible.

Core Neurotransmitters & Transporters

Dopamine (reward), Noradrenaline (CV stimulation), Serotonin (mood, appetite, thermoregulation).
Targets: post-synaptic receptors, plasma-membrane transporters (DAT, NET, SERT), vesicular transporter (VMAT), MAO enzyme.
Inhibitors: cocaine (non-transported blocker); amphetamines (substrate-type releasers + VMAT/MAO actions).

Stimulant Summary

Both natural & synthetic drugs elevate catecholamine/5-HT signalling by blocking re-uptake or promoting release.
Consequences: addiction (dopamine pathway), psychosis, cardiovascular strain, possible neurotoxicity.

Hallucinogens

Sources

Natural: cactus (mescaline), mushrooms (psilocybin).
Synthetic: LSD, designer phenethylamines (e.g. DOM).

Desired vs Unwanted Effects

Desired: ↑ energy, creative thinking, sensory awareness, vivid visuals; non-addictive.
Unwanted: dizziness, noise hypersensitivity, paranoia/panic, flashbacks, toxicity.

Key Compounds

Mescaline vs DOM (2,5-dimethoxy-4-methylamphetamine): phenethylamine hallucinogens.
Psilocybin: structurally resembles serotonin; effects akin to LSD.
LSD: extremely potent (active <1\,\mu\text{g/kg}); 5-HT $2A/2C$ receptor agonist.

Mechanism of Action

Primary target: post-synaptic serotonin receptors $5\text{HT}_{2A}$ (and $2C$ ).
Hallucinogens act as agonists → altered perception, mood, cognition.

Hallucinogen / Designer Drug Summary

Generally non-addictive; produce mood & cognitive shifts, possible hyperthermia and neurotoxicity.
Ethical & therapeutic frontier: MDMA and psilocybin now TGA-approved (Feb $2023$ ) for PTSD and treatment-resistant depression when prescribed by authorised psychiatrists (from July $2023$ ). Phase III study: MDMA-assisted therapy significantly improved severe PTSD (Mitchell et al., $2021$ , Nat Med $27$ : $1025–1033$ ).

Overarching Connections & Implications

Complementary medicines and recreational drugs both illustrate core pharmacological principles: dose–response, PK/PD interactions, receptor specificity vs promiscuity, and the natural-product origins of many therapeutics.
Ethical dimension: balancing autonomy (self-medication, cultural practices) with safety (regulation, evidence-based guidance).
Practical clinical takeaway: comprehensive medication histories must explicitly probe CM and recreational use to avert hidden interactions or toxicities.