Drugs Med-SurgTest 3

7/29/2019 Drugs Med-SurgTest 3

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Medications: Test 3

Fractures: Narcotics, NSAIDs, Stool Softener

Osteoporosis:

- Estrogen replacement therapy (ERT)

- Used to prevent and treat osteoporosis

- For surgical menopause before age 50

- Decreases osteoclastic activity & increases osteoblastic activity

- Can increase risk of endometrial cancer. Advantages: increases bone density, decreases risk of fractures, relief of hot flashes, vaginal dryness, decreases LDL,

increases HDL

Disadvantages: increased risk of urterine ca (if unopposed), increased risk of DVT, possible increased risk of breast

and endometrial cancer

Dose: Estrogen- 0.625 mg, qd, 0.3 mg; Progesterone- 2.5 mg, qd, (if uterus is present)

- Selective estrogen receptor modulators (SERM)

- Treatment and prevention of osteoporosis by mimicking estrogen beneficial effects on bone density.

- Decreases bone resorption

Advantages: increases bone density, decreases fracture risk, no stimulation of breast or endometrial tissue, decreases

LDL

Disadvantages: increased risk of DVT-not for women with history of blood clots, doesn’t treat post menopausalsymptoms-may increase hot flashes, no effect on HDLs

Dose: Raloxifene (Evista) 60 mg, qd

- Bisphosphonates

Alendronate (Fosamax) 5-70 mg once a week dosing

Risendronate (Actonel) 5-30 mg once a week dosing

Ibandronate (Boniva) 150 mg once a month

Primidronate (Aredia) & Zoledronic (IV prep)

- Prevention & treatment of osteoporosis in post menopausal women. Prevention and treatment of steroid-induced osteoporosis

both in men & women, Paget’s disease, hypercalcemia of malignancy

- It absorbs to hydroxypatite and becomes a part of the bone structure. Bisphosphonates prevent bone resorption by inhibiting

osteoclast activity. Take on empty stomach. Take first thing in the morning (30 min before meal). No food or other meds 30 minutes

after taking Bisphosphonates. Take with 8 oz of water only. Remain in an upright position for at least 30 minutes after

taking the drug-result in esophagitis and GI distress. Instruct patient to report chest pain or dysphagia. Separate Ca,

Al, and Mg containing meds by at least 4 hours.

Advantages: increases BMD, decreases fracture risk, no increased risk of breast and uterine ca or

thromboembolic events, weekly or monthly dosing.

Disadvantages: risk of GI disorders, contraindicated in renal failure

- Calcitonin

- Increase in blood calcium increases secretion of calcitonin decrease in blood calcium increases secretion of parathyroid

hormone

Principal effects are to lower serum calcium and phosphate

Salmon calcitonin (Miacalcin, Calcimar) Nasal spray

o It inhibits osteoclast activity, decreases bone resorption thus lowers serum calcium and

phosphate and reduces bone pain, it increases BMD in the spine.

Paget’s disease, osteoporosis, hypercalcemia.

o Side effects: sore, itching, rhinitis. Transient ANV, urinary frequency, flushing of face, palms and

soles of feet. Risk of anaphylaxis.

Take adequate amount of calcium and vitamin D. take in evening. Warm to room

temperature, use alternate nostril. ANV may occur. Report nose bleeds.



Arthritis:

- Osteo: Acetaminophen, NSAIDs, Glucocorticoids-maybe injected directly into the joint directly (not more than every 4-6 months)

- Rheumatoid: Acetaminophen, NSAIDs, glucocorticoids

- Disease Modifying Anti-Rheumatic Drugs (DMARD)

Gold salts, hydroxychloroquine (Plaquenil)-base line eye exam every 6 months, Sulfasalazine (Azulfidine) & D-

penicillamine (Cuprimine)

- Immunosuppressant agents

Imuran, Cytoxan, Rheumatrex

Biologic immunosuppressant

- Gouty: Chemotherapy, thiazide diuretics, aspirin, TB drugs, NSAIDs, corticosteroids, cholchicine, allopurinol

- Colchicine:

Anti-inflammatory effects limited to gout.

Inhibits crystal-induced production of chemotactic factors

Side effects: PO-abdominal cramping, diarrhea, nausea, vomiting. IV- local pain, DIC, tissue damage on

extravasation. Contraindicated- GI, renal, hepatic, or cardiac disease

- Urate lowering drugs

Goal is for serum urate concentrated to be <8 mg/dL

Xanthine oxidase inhibitors-blocks conversion to uric acid

o Allopurinol

Uricosuric drugs- inhibits tubular absorption

o Probenecid or Sulfinpyrazone

Knee & Hip Replacements: pre-antibiotics, enoxaparin (lovenox), fondaparinux (arixtra), Coumadin (Warfarin)

Alzheimer’s Disease:

- Acetylcholinesterase Inhibitors: selectively inhibits acetylcholinesterase which enzymatically degrades acetylcholine which is needed to

be a neurotransmitter dealing with learning and memory.

- Tacrine (Cognex)-one hour before meals (hepatoxic); Donepezil (Aricept)-at bed time; Rivastigmine (Exelon); Galantamine

(Razadyne)-with food, substrate of p450

Adverse effects: Cholinergic related problems: urinary retention, seizure, bradycardia, GI bleeding.

- NMDA-receptor Antagonists - blocks the activation of glutamate receptors and minimizes the adverse effects of excess glutamate

- Metamantine has shown to slow rate of memory loss in both vascular- associated and Alzheimer’s dementia.

Well tolerated. Side effects: confusion, agitation, restlessness, indistinguishable from AD symptoms

CVA:

- Thrombolytics and/or heparin-not for hemorrhagic

- TPA: 3 hours of onset of symptoms to dissolve the clot

- Edema: mannitol, loop diuretics

- Seizures; dilantin, valium, ativan, Phenobarbitals

Increased ICP:

-

Stress ulcers: H2 blockers, Esomeprozole - Furosemide & Mannitol- draw water from edematous tissues into vascular space, Phenytoin

- Glucocorticoids –help relieve cerebral edema

Epilepsy:

- Anti-Epileptic Drugs (AEDs)

- Modification of ion conductances.

Decrease in Sodium, Calcium influx (delay depolarization/prolong repolarization)

Increased Chloride influx (hyperpolarizes membranes)

- Increase inhibitory (GABAergic) transmission

Increased Chloride influx (hyperpolarize membrane)

- Decrease excitatory (glutamatergic) activity



Decrease sodium, calcium influx (delay depolarization/prolong repolarization)

Many CNS drugs act on GABA receptors to effect the frequency and duration of action potentials!

Choosing Antiepileptic Drugs:

- Monotherapy for Partial Seizures:

- Best evidence and FDA indication:

Carbamazepine (Tegretol), Oxcarbazepine, Phenytoin (Dilantin), Topiramate (Topamax)

- Similar efficacy, likely better tolerated:

Lamotrigine (Lamictal), Cabapentin (Neurontin), Levetiracetam (Keppra)

- As shown to be effective:

Valproate (Depakote), Phenobarbital, Felbamate, Lacosamide

- Limited data but commonly used;

Zonisamide, Pregabalin

- Monotherapy for Generalized-Onset Tonic/Clonic Seizures

- Best evidence & FDA indication:

Valproate, Topiramate

- Also shown to be effective:

Zonisamide, Levetiracetam (Keppra)

Phenytoin (Dilantin), Carbamazepine (may exacerbate absence and myoclonic sz)

Lamotrigine (may exacerbate myoclonic sz of symptomatic generalized epilepsies)

- Absence seizures

- Best evidence:

Ethosuximide (limited spectrum, absence only)

Valproate (Depakote)

- Also shown to be effective:

Lamotrigine (Lamictal)

- May be considered as second-line:

Zonisamide, Levetiracetam, Topiramate, Felbamate, Clonazepam

- Myoclonic Seizures

- Best evidence:

Valproate (Depakote)

Levetiracetam (Keppra) (FDA indication as adjunctive tx) Clonazepam (Klonopin) (FDA indication as adjunctive tx)

- Possibly effective:

Zonisamide, Topiramate (Topamax)

Common Side Effects of AEDs:

- Often dose related: dizziness, fatigue, ataxia, diplopia, irritability-Keppra, word-finding difficulty-Topamax

- Weight loss/anorexia: topiramate, zonisamide, felbamate

- Weight gain: valproate (also associated with polycystic ovarian syndrome in young women)

- Carbamazepine, gabapentin, pregabalin

Serious Side Effects:

- Typically idiosyncratic: renal stones (topiramate, zonisamide); hyponatremia (carbamazepine, oxcarbazepine), aplastic anemia

(felbamate, zonisamide, valproate, carbamazepine); agranulocytosis (Carabamazepine (Tegretol)); hepatic failure (valproate, felbamate,lamotrigine, phenobarbital); Anhydrosis, heat stroke (topiramate); Acute closed-angle glaucoma (topiramate)

Phenytoin Adverse Effects:

- Acute toxicity: high IV rate: cardiac arrhythmias + or – hypotension &CNS depression. Acute oral overdose: cerebellar and vestibular

symptoms and signs: nystagmus, ataxia, diplopia vertigo

- Chronic toxicity: dose related vestibular/cerebellar effects, behavioral changes, gingival hyperplasia, GI disturbances, Sexual endocrine

effects, osteoporosis, hirsutism, hyperglycemia

- Drug Interactions:

Sulfonamides, valproate and phenylbutazone: displace phenytoin from binding sites

Cimetidine, disulfiram, doxycycline, isoniazid, phenylbutazone, sulfas, Warfarin, chloramphenicol: inhibits phenytoin

metabolism



Barbiturates & carbamazepine, pyridoxine, theophylline, alcohol: enhance phenytoin metabolism

Phenytoin decreases serum levels of: carbamazepine, chloramphenicol, corticosteroids, haloperidol, quinidine,

theophylline, oral contraceptives, Warfarin

Valproates:

- Precautions & Contraindications:

- Pregnancy category D associated with spina bifida. Uncommon but may impair platelet aggregation (bleeding time maybe

prolonged). Can cause bone marrow suppression (Baseline CBC & regular monitoring). Can cause false positive ketone urine

test in diabetic patients. Heptotoxicity and liver failure-Do not take with alcohol!

Carbamazepine Drug Interactions:

- Increase carbamazepine levels via decreased metabolism: cimetidine, erythromycin, isoniazid

- Decrease carbamazepine levels via increase metabolism: phenytoin, valproic acid

- Carbamazepine decreases drug levels: Warfarin, oral contraceptives, doxycycline, phenytoin, haloperidol

- Carbamazepine increases drug levels: cimetidine, isoniazid

- Lithium induces carbamazepine toxicity

Phenobarbital Drug Interactions:

- Increase Phenobarbital levels, acute ethanol ingestion, chloramphenicol, valproic acid

- Decreases Phenobarbital levels via increased metabolism, chronic alcohol ingestion, pyridoxine, rifampin

- Barbiturates decrease serum levels: tricyclics, Warfarin, beta blockers, oral contraceptives, digoxin, doxycycline, metronidazole,

theophylline

Multiple Sclerosis

Immunomodulators

- 4 drugs currently available. Recommended for all patients with relapsing-remitting MS and with secondary progressive MS experiencing

acute exacerbations. Self injected.

- Inferferon Beta 1a (Avonex and Rebif): is a protein that is a replica of human interferon. It suppresses the immune system and

helps to maintain the blood-brain barrier. You inject Avonex into the muscle once a week and Rebif is injected under the skin 3

times a week. This drug is useful to people who have definite progressive MS. (T cells can’t get back in, suppresses anti-

inflammatory cytokine. Cytokines communicate between WBCs).

- Interferon Beta 1b (Betaseron): is slightly different from our own interferon. This medication does the same thing as beta 1a,

but is injected just under the skin every 2 days. This is also given to people who have definite progressive MS.

Adverse Effects of Interferon:

Flu-like reaction, hepatotoxicity, myelosuppression, injection-site reactions, depression

- Glatiramer Acetate (Copaxone): “is a small fragment of a protein that resembles a protein in myelin.” Protects myelin by

inhibiting immune response to myelin basic protein (competitive binding to APC). It decreases the reoccurrence of relapse. It is

injected just under the skin every day-patient teaching! There is no flu like symptoms but occasional redness may occur at the

injection site. A few amount of people do experience brief shortness of breath.

Immunosuppressants:

- Only 1 approved by the FDA-Mitoxantrone (Novatrone)

- More toxic than immunomodulators. Produces greater suppression of immune function: myleosuppression, hepatotoxicity,

cardiotoxicity, fetal harm, Pancytopenia (risk for bleeding, infection & anemia)

- Monitor: perform CBC at baseline and prior to each dose. Perform LFT at baseline and prior to each dose. Perform pregnancy

test prior to each dose. Determine LVEF: prior to 1st

dose, prior to all doses once the cumulative dose has been reached.

Whenever signs of CHF develop (signs at 30% of ejection function; normal at 60-70%)

- Imuran; Cytoxan: suppresses immune system. Watch for bone marrow suppression (Pancytopenia-infections, fatigue/anemia, bleeding)



Supportive Drugs for MS:

Spasticity-Baclofen, Tizanidine, Diazepam (Valium), Dantrolene

Optic Neuritis-Methylprednisolone, Oral steroids

Fatigue-antidepressant, amantadine

Pain-Codeine, Aspirin

Sexual dysfunction-Viagra

Tremor-Primidone, Propanolol

Parkinson’s Disease

2 major categories:

1) Dopaminergic agents

a. By far the most commonly used for PD. Promotes activation of dopamine receptors

b. Levodopa (Dopar) & Lepodopa/Carbidopa (Sinemet)

Dopamine + Carbidopa (Sinemet): Dopamine (DA) cannot cross BBB. Given as its precursor, levodopa or L-dopa, which

is converted to DA by dopa-decarboxylase.

Levodopa (L-dopa)-can cross BBB! Dopamine (DA) by dopa-decarboxylase

Carbidopa inhibits peripheral decarboxyalse which is an enzyme that breaks down L-dopa. Thus, lower doses with

fewer systemic side effects have the same beneficial CNS effects. Drug of choice (most effective agent to date). Most

effective for bradykinesia, poor for tremor.

Side Effects:

o “Wearing off effect”-effectiveness wanes after 2-5 years. Initially, L-dopa effects last 6 hours after

PO dose. Reduces to 3 hours after 2 years. Only 2 hours after 5 years of use . Remedy: “drug

holiday” taper off over 3-4 days.

o “On-off phenomenon”-fluctuating response to medication. Patient typically worsens suddenly for

half hour then improves. Remedy: decrease dose and increase frequency. Sustained release

Sinemet-CR may help. Bromocriptine, pergolide and selegiline may help. Palidotomy may help

(surgery).

o N/V common, psychiatric disturbances: hallucinations, confusion, nightmares are common.

Tardive Dyskinesia (Michael J Fox)-orofacial in elderly, lip smacking, eye rolling, limb

chorea/dystonia in younger patients. Overdose-GI upset, choreic movements. Can cause increase

in IOP-contraindicated for glaucoma patients, can cause cardiac Dysrhythmias, hypertension

- Interaction of Sinemet: Pyridoxine (B6)-increases peripheral breakdown of levodopa. Concomitant administration with Mono

Amine Oxidase Inhibitor (MAOI)-antidepressant

Can lead to hypertensive crisis.

Levodopa: promotes dopamine synthesis

Dopamine agonists: stimulate dopamine receptors directly. Used for patients requiring larger doses of levodopa. Those experiencing motor

fluctuations.

- Ergot Derivatives:

- Bromocriptine (Parlodel): stimulates primarily D2 DA post synaptic receptors. Acts as weak D1 antagonist. Causes Vasospasm!-

Contraindicated in patient with PVD/CAD!!*

- Pergolide (Permax): more potent than bromocriptine. Directly stimulates both D1 & D2 receptors. May reduce “on-off”

phenomenon. Hypertensive patients shouldn’t take this.

- Non-Ergot Derivatives:

- Bind selectively to dopamine D2-like receptors and activate D3 receptors which have unknown function.

Parmipexole (Mirapex): has activity at D2 & D3 receptors

Ropinirole (Requip): Strong D2 receptor agonist. Does not cause vasospasm. For patient with PVD.

Selegiline (Eldepryl) & Rasagiline: inhibits dopamine breakdown in the brain by inhibiting MAO type B. Selegiline metabolized into amphetamine

Amantadine (Apokyn): promotes dopamine release. These drugs stimulate the actions of dopamine in the brain, reducing the symptoms of

Parkinson’s disease (PD). 0.2-0.6 mL sub-Q prn maximum 5 times per day. Rescue med for acute, intermittent hypomobility, and off episodes (end

of dose wearing off and unpredictable on/off episodes). Significant improvement in mobility at 20 minutes. Half life 40 minutes. Pregnancy

category C. RESCUE MED.



- Cross sensitivity with Zofran. Severe N/V-start Tigan 3 days prior to initiation of therapy. Hallucinations, sudden sleep episodes, syncope,

MI, Cardiac arrest, Priapism, Abuse potential

COMT inhibitors: enhances effects of levodopa by blocking its degredation

- Methylation of Levodopa by this enzyme is a minor pathway of levodopa metabolism. This enzyme increases to compensate for a

decrease in Dopa-decarboxylase with Carbidopa. Blocking COMT will increase peripheral blood level of levodopa and greater

concentration of brain dopamine. Entacapone & Tolcapone

2) Anticholinergic agents

a. Prevents activation of cholinergic receptors. Blockage of cholinergic transmission produces effects similar to augmenting

dopaminergic transmission (balances dopamine/Ach ratio).

b. Benztropine (Cogentin)

Myasthenia Gravis (MG)

Anticholinesterase Test: Edrophonium (Tensilon)- Rapid onset of 30 seconds. Short duration 5 minutes. Draw up 10 mg, Administer 2 mg. Monitro

for adverse symptoms. Administer remaining 8 mg. Improvement of weak muscles that last 5-10 minutes. Test positive.

Anticholinesterase Drugs: first line treatment for symptoms of MG. Do not treat the underlying disease. Pyridostigmine (Mestinon) no standard

dose. Neostigmine (Prostigmin)- seldom use. *Atropine antidote for cholinesterase (ChE) inhibitor drugs. Must be available.

- Pyridostigmine (Mestinon): last 3 to 6 hours. Goal to produce maximal muscle strength with minimal side effects.

- Muscarinic Receptors- cholinergic (parasympathetic acetylcholine) receptors come in variety of types. One type is muscarinic receptors

or mAChRs. Main end receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system.

Stimulation of muscarinic receptors causes parasympathetic ANS responses.

- Side effects: GI: heartburn, belching, abd cramps, increased peristalsis, diarrhea, N&V. GU: involuntary micturiction, increased

tone and motility of uterus. CV: bradycardia, Vision: blurred, constricted pupils. Pulm: bronchoconstriction/bronchospasm,

increased bronchial secretions, wheezing cough. Other: profuse sweating, increased salivation.

Immunosupapression: For those who do not respond to anticholinesterase drugs: Prednisone, Azathioprine (Imuran), Cyclophosphamide (Cytoxan)

Guillain Barre

Plasmapheresis (Plasma exchange)

Intravenous Immune Globin-use as immunosuppressant

IVIg

Drugs Med-SurgTest 3

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