Plant Poisons: Digitalis Overview

Plant Poisons

• Plant poisons are substances produced by plants that can cause harm or even death if ingested or otherwise come into contact with the body.
• Digitalis is a cardiac glycoside with a complex pharmacotherapy history.

Digitalis

• Cardiac glycosides are active principles in many plants.

• These active principles include digitalis purpurea (purple foxglove), digitalis lanata (white foxglove), Mediterranean sea onion (sea squill), and oleander.

• Digitalin has several active compounds: digoxin, digitoxin, digitalin, and digitonin. Digoxin is the most commonly prescribed digitalis preparation.

• Digoxin treats congestive heart failure and atrial arrhythmias, and comes in 0.125mg or 0.25mg tablets.

• Digitalis poisoning can occur accidentally from therapeutic overdose or from accidental ingestion by children. Suicide is also a factor.

• Mechanism of Action (Therapeutic Dose): a) lengthens the diastolic period to improve heart filling (negative chronotropic); b) increases systolic power to improve contraction (positive inotropic); c) increases renal blood flow.

• Mechanism of Action (Toxic Dose): a) cardiac poison; b) gastrointestinal (GI) issues; c) visual problems; d) central nervous system (CNS) problems.

• Pathophysiology: Inhibits Na+-K+ ATPase which leads to increased intracellular sodium, calcium, and in acute toxicity only, hyperkalemia. In chronic toxicity, potassium levels are usually normal or low.

• Clinical Presentation (Cardiac): Arrhythmias (most frequent), including atrial tachycardia, flutter, fibrillation, ventricular extra systoles, tachycardia, and fibrillation. Brady arrhythmias also include sinus bradycardia, AV block, and sinus arrest.

• Clinical Presentation (GIT): anorexia, nausea, vomiting, colic, and diarrhea.

• Clinical Presentation (Visual): Greenish-yellow vision (rods & cones affection).

• Clinical Presentation (CNS): Headache, delirium, disorientation, drowsiness.

• Cause of Death: Arrhythmias and cardiac arrest.

• Investigations: ECG, continuous cardiac monitor, electrolyte levels, hyperkalemia (acute), hypokalemia (chronic), kidney function tests, digoxin level (therapeutic level is 2ng/ml; >15ng/ml is serious).

• Treatment: I) Prevention from further exposure; II) Supportive measures (ABCs, electrolyte balance, treating arrhythmias); III) GI decontamination (lavage, charcoal, cholestyramine); IV) Physiological antidote (Digibind).

Cannabis Sativa

• Cannabis sativa is a psychoactive drug (psychedelic, psychotomimetic, hallucinogen) used medicinally and recreationally.

• Cannabis sativa comes in various forms such as: hashish (dried resin from flower tops), hashish oil (dark viscous liquid concentrate from cannabinoids from solvent extraction), bango (dried leaves), marijuana (a mixture of crushed leaves, flower, and stem), and sinsemilla (mixture of flowering tops and leaves of cultivated, unfertilized female plants). THC content is 8-11%.

• The primary psychoactive compound is delta-9-THC (delta-9-tetrahydrocannabinol). Other constituents include cannabinol and cannabidiol.

• Cannabis Sativa is administered by smoking (cigarettes or shisha), ingestion (alone or with coffee/tea), or inhalation (burnt in a closed container). It can also be administered as tablets (marinol-dronabinol).

• Pharmacokinetics: absorption via inhalation or ingestion; high lipid solubility; rapidly distributed to brain and adipose tissues; metabolism by liver; excretion through urine and stool.

• Condition of Poisoning: accidental overdose.

• Mechanism of Action: The exact mechanism is not completely understood, but receptors for THC are in basal ganglia, cerebral cortex, cerebellum, and hippocampus. THC stimulates sympathetic receptors and inhibits parasympathetic receptors, leading to CNS stimulation and depression, dependent on mood, THC concentration and route of administration.

• Clinical Presentation (Mental): euphoria, floating feeling in air, talkativeness, sexual or erotic dreams, increase in special senses (auditory, touch, olfactory), dysphoria (replacement of euphoria with depression effect), disorientation of time and space.

• Clinical Presentation (Physical): dilated pupils, conjunctival congestion, tachycardia, orthostatic hypotension, respiratory depression; increase appetite, dry mouth, urinary frequency.

• Cause of Death: central asphyxia and car accidents.

• Investigations: Routine lab tests including blood and urine tests looking for THC.

• Treatment: Supportive measures (ABCs, especially respiration care), GI decontamination (gastric lavage, charcoal), no specific antidote, symptomatic measures (reassurance, mild sedation if needed), psychiatric follow up.

LSD

• LSD is an ergot alkaloid, a psychoactive drug (psychedelic, psychotomimetic, hallucinogen)

• It's derived from Claviceps purpurea, but many synthetics are also available.

• It is extremely potent and given orally (25-50µg).

• It has a lack of odor and color. It can be dissolved in liquid or solid form.

• It creates a rapid production of tolerance (tachyphylaxis) and recovery. There is cross-tolerance with mescaline and psilocybin.

• Mechanism of Action: poorly understood but primarily acts on the central nervous system. Changes in mood and behavior, effects on pyramidal and extrapyramidal systems, and sympathetic/parasympathetic systems are all noted. LSD has noticeable sensory effects.

• **Clinical Presentation:(Mental) : ** Euphoria, hysterical laughter and dysphoria, sadness and crying

• Clinical Presentation (Sensory): visual disturbances (intensified color, flat surfaces appearing in 3D, objects undulating or flowing), along with abnormal auditory, tactile, olfactory, and gustatory sensations.

• Clinical Presentation (Sympathetic): Mydriasis, hyperthermia, piloerection, hyperglycemia, tachycardia, and hypertension. Time perception alteration and ego disruption, and fear of self-destruction or feelings of body parts being foreign and unnatural.

• Clinical Presentation (Acute): acute panic reaction, flashbacks, prolonged psychosis, schizophrenia-like symptoms.

• Cause of Death: common suicide

• Treatment: Quiet environment and lighting, reassurance, sedation (Diazepam), and antipsychotics (Chlorpromazine).

Drug Dependence

• Drug of abuse: Use of a drug (oral, smoking, snuffing, injection) to alter mood or consciousness.

• Substance of abuse: Any drug used for non-medical purposes to relieve discomfort or create a sense of well-being.

• Drug habituation: desire to take a drug without compulsion, with some psychological dependence and detrimental effects.

• Drug addiction (dependence): Compulsive use leading to physical and/or psychological dependence.

• Mechanism of drug dependence: Addiction may be a cellular phenomenon with adaptation in cells due to drug use. Drug withdrawal or concentration change can lead to disturbed or abnormal function.

• Characteristics of dependence:

• Compulsive desire to take the drug.

• Tolerance.

• Physical dependence.

• Psychic dependence.

• Withdrawal symptoms.

• Detrimental effects on individual, family, and society.

• Methods of drug abuse:

• Nasal insufflation (heroin).

• Inhalation (cocaine).

• Smoking (hashish).

• Intravenous injection (morphine).

• Dissolving tabs and intravenous injection.

• Types of addicts:

• Therapeutic addicts.

• Professional addicts.

• Street addicts.

• Congenital addicts.

Explore the dangers of plant poisons, focusing on Digitalis and its effects on the heart. Learn about the active compounds in digitalis, their therapeutic uses, and the risks of poisoning. This quiz will deepen your understanding of both the medicinal and harmful aspects of these plant-derived substances.