Test 4: 49 Rx Flashcards by jillian Bastidas

how do calcium channel blockers cause toxicity

Prevents Ca influx into cell, which prevents contraction.

Effects:
– Hypotension
– Bradycardia, reflex tachycardia
– Pulmonary edema
– Hyperglycemia

verapamil, diltiazem, amlodipine
can be sustained release med

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how to treat calcium channel blocker toxicity

Calcium gluconate
Vasopressors
Insulin/dextrose - normally the myocardium is fatty acid dependent for energy – however, calcium channel blocker toxicity makes the myocardial cells carbohydrate dependent but at the same time unable to utilize carbohydrates due to the lack of insulin.

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what are some common decongestants

Pseudoephedrine (PSE)
Phenylephrine (oral)

stimulate ⍺1 receptors

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signs of decongestant overdose

Pseudoephedrine (PSE)

stimulates both alpha and beta receptors
- B stimulation results in tachycardia, tachyarrhythmias.
- Alpha: peripheral vasoconstriction, hypertension
Inhibits bladder emptying (stimulates receptors that tighten the bladder sphincter). PSE been used for canine urinary incontinence.

Phenylephrine (oral)

hyperactivity, vomiting, mydriasis, hyperthermia, disorientation, tachycardia (and sometimes reflex bradycardia)

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species specific for decongestants

dogs very senstive

PSE-toxicosis can lead to agitation if mixed with diazepam

narrow therapeutic dose: 1.5 mg/kg 2-3x daily for urinary incontinence in dogs, clinical signs 5-6 mg/kg, death 10-12 mg/kg

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treatment for decongestant toxicity

decontamination and symptomatic supportive care (to manage sx such as tachycardia, bradycardia, excess CNS stimulation).

Acepromazine, chlorpromazine or phenobarbital may be preferable to a benzodiazepine to control tremors, seizures and nervousness.

do not use diazepam in dogs can cause agitation

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what are some common antihistamines

Chlorpheniramine
Diphenhydramine (po and dermal) Benadryl® 2% cream (2 gm/100gm = 100 mg/5gm tsp)
Meclizine

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clinical signs of antihistamine toxicity

CNS depression, dry mucous membranes, ataxia
– Anticholinergic effects (but not meclizine – in piperazine class)

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treatment of antihistamine toxicity

decontamination and
symptomatic supportive care

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risk factors for renal toxicity from NSAIDs

pre-existing renal disease
hypovolemia (vomiting, dehydration)
hypotension

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why can NSAIDs cause renal damage

can cause decreases renal blood flow

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clinical signs of NSAID toxicity

GI: vomiting, diarrhea, anorexia, hematemesis, melena
hepatic: lethargy, weight loss, liver enzyme elevation
renal failure

Narrow margin of safety in both dogs and cats.

NSAIDs can cause decreased renal blood flow, decreased gastric mucous production and decreased platelet aggregation

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Cats 2x as sensitive as dogs to NSAIDs due to limited — ability

glucuronyl-conjugating

no advil, tylenol(acetaminophen) or bayer

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treatment for NSAID toxicity

Decontamination and symptomatic supportive care.

GI protectants (avoid bismuth subsalicylate) - Antiulcer meds that have been used: sucralfate, misoprostol, H 2 antagonists
Fluids

NSAIDs can cause decreased renal blood flow, decreased gastric mucous production and decreased platelet aggregation

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clinical signs of acetaminophen toxicity

can be asymptomatic

vomiting, anorexia, methemoglobinemia, edema

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species specific acetaminophen toxicties

Dogs are more prone to hepatic necrosis than cats.

Acetaminophen is the most common drug-related cause of Heinz body formation in cats.- methemoglobinuria- liver damage

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treatment for acetaminophen toxicity

N-acetylcysteine (NAC) - need to give within 8 hrs

Symptomatic treatment (cats with methemoglobinemia may require methylene blue)

Although methylene blue is an oxidizing agent, it can be given to cats but at careful low doses.
Cimetidine and ascorbic acid(Vit C) are not accepted antidotes for acetaminophen poisoning.

Cimetidine and ascorbic acid are not accepted antidotes for —poisoning.

acetaminophen

should use NAC within 8 hrs of ingestion

can treat methemoglobinemia in cats with methylene blue

what in bengay can cause toxicity

aspirin (methyl salicylate)

1 tablespoon= 6.3 grams of aspirin!!

what is toxic in pepto bismol

bismuth subsalicylate (aspirin)

1 tablespoon= 130 mg of aspirin!

clinical signs of aspirin toxicity

vomiting, hyperventilation, fever, hypo or hyperglycemia, metabolic acidosis

if pt becomes acidotic ASA can move into the brain and cause seizures

ASA in petobismol and bengay

— are more susceptible to ASA poisoning than — due to saturation of elimination pathways

Cats

dogs

range of toxicity for ASA

Dogs

Therapeutic dose: 10-20 mg/kg q 48 hrs).
Gastric ulcers with 100mg/kg/day for 1-2 weeks

Cats

As little as 25 mg/kg can cause acute toxicity

treatment for aspirin toxicity

Decontamination and symptomatic supportive care

Sodium bicarbonate increases urinary elimination of aspirin and decreases brain concentrations of aspirin. (try to alkanize pt)

what are some common ⍺2 agonists

clonidine visine ## Footnote imidazole decongestant

symptoms of imidazole decongestant toxicity

* CNS depression * Apnea (not breathing) * Bradycardia * **Hypotension** due to **central** alpha 2 stimulation. But **hypertension** if **peripheral** alpha-2 stimulation. * Miosis (pupil constricted) ## Footnote ⍺2 agonist: clonidine, visine

treatment for imidazoline decongestants

decontamination and symptomatic supportive care * Naloxone may be of benefit for ingestions of imidazolines (has been reported to sometimes reverse coma and hypotension in humans) ## Footnote ⍺2 agonist: clonidine, visine

clinical signs of antacids toxicity

aluminum hydroxide, magnesium hydroxide, calcium carbonate **minimally toxic** Only symptomatic treatment of the GI effects is needed.

clinical signs of fleet enema (sodium phosphate) toxicity

hyperphosphatemia, hypernatremia, dehydration and shock. concern is fluid and electrolyte losses.

what causes toxicity in Kaopectate

now contains bismuth subsalicylate (aspirin) ## Footnote pepto bismol also has bismuth subsalicylate Kaopectate is an antidiarrheal

side effects of imodium (loperamide) toxicity

can have opioid-like effects (structurally similar to both haloperidol and diphenoxylate). antidiarrheal med

treatment for imodium toxicity

**Naloxone** may be effective **Therapeutic dose in dogs is very small** (0.08 - 0.1 mg/kg po q 12 hrs) versus the 2mg capsule available for humans.

lomotil toxicity symptoms

opioid that contains anticholinergic (try to stop abuse) antidiarrheal med

treatment for antidiarrheal med toxicity

decontamination and symptomatic supportive care. * Naloxone – for diphenoxylate (Lomotil®) and loperamide (Imodium®)

topical zinc oxide toxicity

**not toxic** unless chronic or very large amount without emesis found in diaper rash ointment, sunscreen, calamine lotion, astringents. treatment: supportive care (watch and wait)

clinical signs of calcipotriene toxicity

**Synthetic vit D3** Dovonex® (calcipotriene): human psoriasis treatment – **Ingestion**: Severe hypercalcemia, renal failure, soft tissue mineralization (in dogs) – **Topical use**: only 5-6% is absorbed dermally **vomiting, CNS depression, anorexia, diarrhea, polyuria** ## Footnote Special note: **weeks of treatment may be required**. Death can occur weeks after an apparent recovery secondary to calcification of cardiac tissue.

treatment for calcipotriene toxicity

* Decontamination * Supportive care (renal failure). * Treat elevated serum calcium and phosphorus * Bisphosphonates (Aredia® - pamidronate is used in humans to treat malignancy-related hypercalcemia) ## Footnote Special note: **weeks of treatment may be required**. Death can occur weeks after an apparent recovery secondary to calcification of cardiac tissue.

clinical signs of 5-fluorouracil toxicity

very toxic- 1/2 a tube deadly Ingestion : * severe, intractable seizures, * vomiting and GI mucosal sloughing. * delayed severe leukopenia (WBC less than 1 x 103) Topical: * toxicity has also occurred following dermal application to dogs and cats Prognosis is poor since a large % of dogs **die from intractable seizures**

treatment for 5-fluorouracil toxicity

* Seizures rarely respond to diazepam; (success reported in dogs: barbiturates, isoflurane, propofol) * Filgrastim (for severe leukopenia) Weeks of monitoring may be required (delayed leukopenia).

list of meds dangerous in small amounts for dogs

**Dogs** NSAIDS Pseudoephedrine Caffeine Albuterol **Both species** 5-fluorouracil Calcipotriene Isoniazid

list of meds that are toxic in small amounts for cats

**Both species** 5-fluorouracil Calcipotriene Isoniazid **Cats** Acetaminophen Benzocaine NSAIDS ASA In general, oxidant drugs that induce Heinz body formation (examples: phenols, propofol, phenazopyridine, methylene blue)