Pharmacodynamics is the process by which medication works on the body. Medications either stimulate the receptors or block them. An agonist is a medication that causes stimulation of a receptor, and an antagonist is a medication that blocks receptors. Some medications may add electrolytes and others may target bacteria (antibiotics), and antifungal medication targets fungi. They may also change the concentration of substances in certain body compartments. An action is the intended therapeutic effect the medication is expected to have on the body. Pharmacokinetics of a medication are the actions of the body upon the medication. Onset of action — time from medication administration until clinical effects occur. Route of administration will often have a significant effect on both the pharmacodynamics and the pharmacokinetics. Duration — length of time that clinical effects persist. Elimination — how medication or chemicals are removed from the body. Patients with liver or kidney disease will have altered pharmacokinetics of many medications compared to healthy individuals. Peak — the point or period when maximum clinical effect is achieved.
Indications are the reasons or conditions for which a particular medication is given. For example, nitroglycerin relaxes the walls of all blood vessels, increasing the blood flow and supply of oxygen to the heart muscle. Nitroglycerin helps with angina — chest pain. Contraindications are when a medication would harm the patient or have no positive effect. Aspirin is good for treating pain or a heart attack (acute myocardial infarction), but if there is some type of bleed it would be contraindicated because aspirin is a blood thinner and that would make the bleed worse. Hypotension is an absolute contraindication for nitroglycerin because it would lower the blood pressure by relaxing the blood vessel walls. Sometimes the weight of the medication outweighs the contraindication; for example, glaucoma is a relative contraindication for many drugs, but you would still administer epinephrine (EpiPen) in cases of anaphylaxis (allergic reaction). Adverse effects are any actions of a medication other than the desired ones. Adverse effects can occur even when medications are administered correctly. Unintended effects are undesirable but pose little risk to the patient, such as a headache. Untoward effects can be harmful, like hypotension.
Enteral medications enter the body through the digestive system, typically in the form of a pill or liquid. They absorb slowly because of delayed absorption. Aspirin/antipyretics (fever-reducing medications). Parenteral medications enter by a route other than the digestive tract. They are in liquid form and are generally administered using syringes and needles. Per rectum literally means through the rectum, most commonly used with children because of easier administration and more reliable absorption. Medications that control seizures when it is impossible to administer them intravenously have rapid onset. Oral — taken by mouth. Slow onset but can be surprisingly fast sometimes depending on the substance; unpredictable absorption. Intravenous (IV) injection means into the vein. This is the fastest way to deliver a chemical substance. Intraosseous (IO) injection reaches the bloodstream through the bone marrow; painful. The IO route is used most often in patients who are unconscious as a result of cardiac arrest or extreme shock. Subcutaneous injections mean under the skin, given into the fatty tissue between the skin and the muscle. They absorb more slowly and their effects last longer. Daily insulin and some forms of epinephrine can be given by the subcutaneous route. Intramuscular (IM) injection — intramuscular means into the muscle. Usually, medications that are administered by IM injection are absorbed quickly. Auto-injector, EpiPen auto-injector. Inhalation — some medications are inhaled into the lungs so that they can be absorbed into the bloodstream more quickly. Others are inhaled because they work in the lungs, minimizing the effects on other body tissues. Sublingual means under the tongue, nitroglycerin tablets. Faster than the oral route and protects meds from chemicals in the digestive system. Transcutaneous (transdermal) — absorbed through the skin like a nicotine patch or lidocaine. Intranasal — the route is a liquid medication, aerosolized and administered into a nostril — the mucous membranes lining the sinuses.
Tablets and capsules — given by mouth to adult patients. Solution is a liquid mixture of one or more substances that cannot be separated by filtering or allowing the mixture to stand. Given by mouth and absorbed quicker because the medication is already dissolved. IV, IM, or subcutaneous injection. Suspension is a mixture that has been ground into fine particles and dissolved into a liquid. Tylenol suspension is given to infants and children. May be given via IM or subcutaneous injection. Metered-dose inhalers are liquids or solids broken into small enough droplets or particles so they can be inhaled. Topical medications are lotions, creams, and ointments; that is, they are applied to the surface of the skin and affect only that area. Transcutaneous medications are designed to be absorbed through the skin, or transcutaneous; in contrast to most topical medicines which work directly on the application site, transdermal medications are usually intended for systemic whole-body effects. Be careful when touching with your bare skin. A gel is a semiliquid substance that is administered orally in capsule form or through plastic tubes. Oxygen — gaseous meds are neither solid nor liquid. The medication most commonly used in gaseous form is oxygen.
After administration, you must reassess to see if it worked or if there are adverse effects. You must have an order from medical control; it is important that you repeat the order back to the physician. Echo technique. You must understand what the physician wants you to do. Err on the side of caution. Other ways to receive orders to administer or assist with medication are through indirect or offline medical control. Protocols are documents that contain standing orders for the administration of certain medications in specific circumstances. A protocol may direct you to use a nonrebreathing mask to deliver oxygen at 15 L/min to a patient who is having respiratory difficulties. You can do this without calling online medical control if the patient meets the criteria of the protocol.
Ensure: Right patient. Right medication and indication — verify the proper medication and prescription. Make sure the patient doesn’t have any contraindications for the medication. Right dose — verify the dose, 324 mg of aspirin; you need to read the bottle to determine how many milligrams are in each tablet. Good idea to have your partner confirm the dosage before administering it. Right route — make sure the patient doesn’t swallow a sublingual nitroglycerin tablet. Right time — check the expiration date and condition of the medication. Expiration date. If you find any discoloration, cloudiness, or particles in a liquid medication, you should not use it. Reassess vital signs every 5 minutes. Right education — inform the patient of the medication you intend to administer and confirm if they have any medication allergies or unusual sensitivity to medication. Right to refuse — patients with decision-making capacity can decline or refuse proposed intervention or medication; in unresponsive patients, evaluate if they have an advance directive. Right response and evaluation — watch for anticipated response or adverse medication effects when reassessing. Right documentation — work is not done until the paperwork is done; document your actions and the patient’s response.
Use a verbal cross-check procedure that verifies you are giving the right drug to the right patient at the right dose. It uses closed-loop communication and provides a time-out to reflect that proper drug administration is being performed. Communicate with partner by saying med check → Ready → I am going to give medication name, dose, and route for indication → contraindication → None if there are none → Volume and show the partner the medication container and the syringe, tablets, or device that is used to measure the dose → if partner agrees, they state give it.
EMTs often carry oxygen, oral glucose, aspirin, and epinephrine. You can only give these medications under standing orders in a protocol (offline medical control) or a direct order (online medical control). Several different routes. Peer-assisted medication — you are administering meds to yourself or your partner. Exposed to a toxic nerve agent during a terrorism incident — treat self and partner. Nerve agent antidotes are administered via auto-injector. Patient-assisted medication administration — you are assisting the patient with the administration of their own meds like EpiPen, MDI inhaler, or nitroglycerin. EMT-administered medication — medical control, state guidelines, and local protocols will be the determining factors that define the role of the EMT. You may administer when medical control gives you an order. Local medical protocols developed by a medical physician under whom you are working.
Aspirin (Bayer) — Anti-inflammatory and antifever, prevents platelets from clumping, thereby decreasing formation of new clots — Relief of mild pain — Contraindication, recent bleeding, hypersensitive — PO — interactions, patients who are taking anticoagulants — dose 160–325 mg — do not administer for pain caused by trauma.
Ipratropium (albuterol, Proventil, Ventolin) — Stimulates nervous system causing bronchodilation — Asthma/difficulty breathing with wheezing — contraindication, hypersensitivity, tachycardia, chest pain of cardiac origin — Inhalation — adverse effects, hypertension, tachycardia, anxiety, restlessness — increases effects of other nervous system stimulants — 1 to 2 inhalations; wait 5 minutes before repeating dose — patient must inhale all medication in one breath; coach to hold breath for 5 seconds.
Epinephrine (EpiPen) — Stimulates nervous system, causing bronchodilation → indications, anaphylactic reaction — contraindications, chest pain of cardiac origin; hypothermia; hypertension → IM → Adverse effects, hypertension, tachycardia, anxiety, restlessness → increases effects of other nervous system stimulants → 0.3 mg for adults, 0.15 mg for children → medication will last approximately 5 minutes; do not repeat dose; ensure ALS is en route for continuing treatment.
Naloxone (Narcan, EVZIO auto-injector) → Action, stimulates nervous system → Opioid poisoning → Contraindications, hypersensitivity → IM, IN — Adverse effects, nausea, vomiting → Additional doses may be required for severe opioid overdoses → 2 mg IN or IM auto-injector → Patients may wake up combative.
Nitroglycerin (Nitrostat, Nitromist) → Actions, dilates blood vessels → indications, chest pain of cardiac origin → Contraindications, hypotension, use of sildenafil (Viagra) or another treatment for erectile dysfunction within the previous 24 hours, head injury → SL tablet or spray → Adverse effects, headache, burning under tongue, hypotension, nausea → interactions, increases dilating effects of other blood vessel-dilating medications → 0.3 to 0.4 mg SL; 0.4 mg spray → Ensure ALS is en route. Should always take the blood pressure of a patient before administering nitroglycerin, and systolic blood pressure should be above 100 mm Hg. Should sit or lie with head elevated. If nitroglycerin no longer brings relief when it previously occurred, patient may be experiencing a heart attack (myocardial infarction) instead of an angina attack. Erectile dysfunction medication can have potentially fatal interaction with nitroglycerin because together they can rapidly drop the blood pressure. Erectile dysfunction medications can be taken by men and women, so do not assume based on gender and always ask.
Oral glucose (Glutose) → action, when absorbed provides glucose for cell use → indications, low blood glucose (hypoglycemia) → contraindication, decreased level of consciousness, nausea, vomiting → PO → adverse effects, nausea → no interactions → ½ to 1 tube → patient must be awake, have control of airway, and be able to follow commands.
Oxygen → action, reverses hypoxia, provides oxygen to be absorbed by lungs → indications, hypoxia or suspected hypoxia → contraindication, very rarely withheld in patients with COPD; do not use near open flames, as O₂ supports combustion → inhalation → adverse effects, decreased respiratory effort in rare cases in patients with COPD → interactions, can support combustion → Dose, 28 to 100% O₂; no open flames; do not withhold oxygen from patients in respiratory distress.
Acetaminophen (Tylenol) → action, analgesic and fever reducer → indications, relief of mild pain or fever, headache, muscle aches → contraindication, hypersensitivity → PO → adverse effects, allergic reaction → interactions, take caution to avoid potential overdosing; many OTC medications contain acetaminophen → 500 to 1000 mg every 4 hours as needed → weight of child is more important than age.
Diphenhydramine (Benadryl) → action, antihistamine (blocks histamine) → Mild allergic reactions → contraindication, asthma, glaucoma, pregnancy, hypertension, infants → PO → Adverse effects, sleepiness, dry mouth and throat → interactions, do not take with alcohol or MAO inhibitors (type of psychiatric medication) → 25 to 50 mg → Can use in severe allergic reaction; however, epinephrine is administered first.
Ibuprofen (Advil, Motrin, Nuprin) → NSAID that reduces inflammation and fever; analgesic → indication, mild pain or fever, headache, muscle aches → contraindication, hypersensitivity → PO → adverse effects, nausea, vomiting, stomach pain, bleeding, allergic reactions → interactions, do not take with aspirin → 200 to 400 mg every 4 to 6 hours; dose is weight-based in children → Do not take for pain caused by trauma; weight of child is more important than age.
- Common drugs
- alprazolam(Xanax) – anxiety disorders
- Amlodipine (Norvasc) – Treats high blood pressure or cardiac conditions
- amoxicillin (Moxatag) – Treats infection cause by bacteria
- aripiprazole(Abilify) – Treats psychosis, depression
- atenolol (Tenormin) – Beta blocker; treats hypertension
- atorvastatin(Lipitor) – Treats high cholesterol
- azithromycin (Zithromax) – Treats infections caused be bacteria
- Buprenorphine and naloxone(Suboxone) – prevent opioid withdrawal
- bupropion(Wellbutrin; Zyban) – treats depression; smoking cessation
- celecoxib(Celebrex) – Treats pain
- Citalopram hydrobromide (Celexa) – Treats depression
- Donepezil HCL(Aricept) – Treats dementia
- Duloxetine (Cymbalta) – Treats depression and anxiety disorders
- escitalopram(Lexapro) – Treats depression and anxiety
- esomeprazole (Nexium) – Treats gastric reflux, heartburn
- etanercept(Enbrel) – Treats rheumatoid arthritis
- Furosemide (Lasix) – Diuretic; treats hypertension, heart failure
- gabapentin(Neurontin) Treats seizures and nerve pain
- metformin (Glucophage) – Treats diabetes
- hydrochlorothiazide(Microzide) – Beta blocker; treats hypertension, heart failure
- hydrocodone (Vicodin) – narcotic analgesic; pain reliever
- Insulin glargine(Lantus) – Medicine used to treat diabetes that is administers subcutaneously
- levetiracetam(keppra) – treats seizures
- levothyroxine (Synthroid) – treats hypothyroidism
- lisinopril(Zestril) – Angiotensin-converting enzyme inhibitor; treats hypertension
- loratadine (Claritin) – Antihistamine
- losartan(Cazaar) – Angiotensin receptor blocker; treats hypertension
- metoprolol (Lopressor) Beta blocker, treats hypertension, heart failure
- montelukast (singulair) – Treats asthma
- olanzapine (Zyprexa) – treats schizophrenia and bipolar disorder
- omeprazole (Prilosec) – Treats gastric reflux, heartburn
- oxycodone(Oxycontin; Percocet) – Treats pain(analgesic)
- pantoprazole(Protonx) reduces stomach acid
- phenytoin (Dilantin) – Treats seizures
- rosuvastain(Crestor) – treats high cholesterol
- salmeterol (Advair) – glucocorticoid beta-2 agonist prevents asthma attacks,COPD
- Sertraline HCL(Zoloft) – Treats depression
- simvastatin(Zocor) – treats high cholesterol
- tamsulosin (Flomax) – Treat urinary disorders related tn enlarged prostate
- Triamcinolone acetonide(Nasacort) – treats inflammatory conditions
- valsartan (Diovan) – Treats high blood pressure and congestive heart failure
- varenicline (Chantix) – Used for smoking cessation
- zolpidem (Ambien) – Treats insomnia
Leave a Reply