Pharmacology Medications and their potential implications in physical therapy Definitions Drug: Any substance that alters physiologic function in the organism, regardless of whether the effect is beneficial or harmful Pharmacology Definitions Pharmacodynamics: the study of the effect that a drug has on the body Pharmacokinetics: how the drug is absorbed in the body, distributed within the body, and eliminated from the body 1
Terminology Dose: how much of a drug the patient is supposed to take at one time Dosage: Total amount of a drug administered over the condition; how much medication is deemed to be efficient in ridding the condition Administration of Meds Orally (most frequent) Advantage: easy, painless Disadvantage: takes a while to be distributed (via digestive system); loses efficiency as it goes through the metabolic system Administration of Meds Sublingual (under the tongue) Advantage: quick response; don t lose potency Rectal Advantage: if patient is vomitting Disadvantage: uncomfortable, embarrassing 2
Administration of Meds Inhalation Advantage: goes directly to the lungs; maximum benefit within 7 seconds Topical Absorbs through the skin, slow response Transdermal Put drug on skin and drive it through using conduction (ultrasound) Administration of Meds Injections Intravenous: injected directly into a vein, circulates rapidly Intra-arterial: injected directly into an artery, more risk than intravenous Subcutaneous: injected under the skin Intramuscular: injected into muscle, takes time to circulate Drug Storage Sites Adipose Tissue: biggest site for drug storage Bones: Storage site for heavy metals and other toxins (ie. Lead) Muscles Organs: Liver & Kidney 3
Medications Major groups of medications prescribed for musculoskeletal conditions: Common Drugs That May Affect an Exercise Program Anticoagulants Blood thinners; prevents clot formation; DOES NOT dissolve clots Adverse reactions: excessive bleeding, bruising, abdominal pain, nausea/vomiting Example: coumadin, warfarin, heparin, lovenox, plavix Common Drugs That May Affect an Exercise Program Antidepressants Increases neurochemicals (ie. Seratonin) Adverse Reactions: sedation, lethargy, muscle weakness; orthostasis and falls, arrhythmias; dizziness, syncope, confusion Example: prozac, celexa, wellbutrin 4
Common Drugs That May Affect an Antihypertensive agents Lowers BP & HR Adverse reactions: hypotension; orthostatic hypotension, dizziness, syncope, lethargy, tinnitus, arrhythmias, brady/tachy cardia, peripheral edema, weakness, fatigue, headache, falls; reduced exercise capacity Example: beta-blockers, accupril, lopressor, monopril Common Drugs That May Affect an Muscle Relaxants: CNS depression, lowers muscle excitability Adverse reactions: drowsiness, dizziness, sedation, muscle weakness, GI upset Example: flexeril, robaxin, soma, skelaxin Common Drugs That may Affect an Non-steroidal anti-inflammatories (NSAIDS) Decreases edema & joint stiffness Adverse reactions: blunts the action of cardiovascular drugs (diuretics, ACE inhibitors, beta blockers); dizziness, sedation Example: advil, aleve, anaprox, daypro, indocin, naproxen, relafen 5
Common Drugs That May Affect an Diuretics Promotes excretion of water; alters sodium / potassium balance in the kidneys, treats HTN or edema due to CHF adverse reactions: headache, hypotension, hyperglycemia, dehydration, photosensitivity Examples: lasix, aldactone Common Drugs That May Affect an Anti-Diabetics: Regulates glucose; elevates insulin levels Adverse reactions: sedation, hypoglycemia, dizziness, muscle cramps, diarrhea Example: metformin, glucotrol, humulin (insulin) Common Drugs That May Affect an Analgesics (pain meds): Decreases pain Adverse reactions: GI upset, nausea, Narcotics: potential for abuse Example: narcotics & opiods, darvocet, dilaudid, morphine, percocet, vicodin, hydrocodone, oxycontin, tylenol, tylenol with codeine 6
Common Drugs That May Affect an Sedatives CNS depression Adverse reactions: altered mental state, sedation, dizziness, lack of coordination Examples:adivan, ambien, restoril Common Drugs That May Affect an Corticosteroids Adverse reactions: Retain fluid, increased BP; prone to osteoporosis, bone fractures; proximal muscle weakness, degeneration of skeletal system Example: prednisone Common Drugs That May Affect an Immuno-suppressants Adverse reactions: confusion, altered mental state, headache, quadriplegia, stroke, seizures; neuropathy, paresthesia; osteoporosis, myopathies Drugs taken after an organ transplant; Imuran 7
Common Drugs That May Affect an Anti-spasticity medications: Reduces tension in the muscles Examples: Baclofen, Valium, Lioresal Pharmacology in Physical Therapy Scheduling patients Scheduling patients for therapy when certain drugs reach their peak effect may enhance the results of the therapy session Analgesics (relieve pain) Drugs that improve motor function Anti-Parkinsonian medications Pharmacology in Physical Therapy Some therapy sessions that require the patient s active participation may be useless if: Scheduled when sedatives reach their peak effect 8
Medications and Exercise Side effects and drug interactions can affect an individual s performance Balance Posture Motor control Endurance Mood Medications and Exercise Medications can effect exercise parameters Heart rate Blood pressure Respiratory rate Check the patient s chart! Then check the Physician s Desk Reference (PDR) 9