Paradoxical hypotension

Possible adverse reactions include headache anorexia nausea vomiting diarrhea palpitations tachycardia angina pectoris toxic reactions (particularly the LE cell syndrome) lacrimation conjunctivitis dizziness tremors psychotic reactions rash urticaria pruritus fever chills arthralgia eosinophilia constipation paralytic ileus lymphadenopathy splenomegaly nasal congestion flushing edema muscle cramps hypotension paradoxical pressor response dyspnea urination difficulty ... 

During initial therapy, headache and postural hypotension may occur, and the nurse must notify the primary health care provider because a dose change may be necessary. The nurse assists patients having episodes of postural hypotension with all ambulatory activities. The nurse instructs those with episodes of postural hypotension to take the drug in a sitting or supine position and to remain in that position until symptoms disappear. Hypotension maybe accompanied by paradoxical... 

Use cautiously in people with acute or chronic respiratory impairment, particularly children, because phenothiazines may suppress the cough reflex. If hypotension occurs, epinephrine is not recommended because phenothiazines may reverse its usual pressor effect and cause a paradoxical further lowering of blood pressure. Because these drugs have an antiemetic action, they may obscure signs of intestinal obstruction, brain tumor, or overdosage of toxic drugs. 

Adverse reactions may include drowsiness ataxia dizziness slurred speech headache vertigo weakness impairment of visual accommodation euphoria overstimulation paradoxical excitement nausea vomiting diarrhea palpitations tachycardia various arrhythmias syncope hypotensive crises allergic/idiosyncratic reactions leukopenia acute nonthrombocytopenic purpura petechiae ecchymoses eosinophilia peripheral edema fever hyperpyrexia chills angioneurotic edema bronchospasm oliguria anuria anaphylaxis erythema multiforme exfoliative dermatitis stomatitis proctitis Stevens-Johnson syndrome bullous dermatitis paresthesias agranulocytosis aplastic anemia thrombocytopenic purpura. 

Paradoxical aggression Headache Hypotension Weight gain Sexual dysfunction... 

There have been reports of excessive hypotension and paradoxical pressor effects following intravenous administration of labetalol. These latter effects may be due to a labetalol-induced blockade of neuronal amine uptake, which increases the concentrations of norepinephrine in the vicinity of its receptors. 

Overdosage may vary from CNS depression, including sedation, apnea, hypotension, cardiovascular collapse, or death to severe paradoxical reaction, such as hallucinations, tremor, and seizures. 

Paradoxical excitement, confusion, palpitations, facial flushing, decreased urination, blurred vision, dizziness, dry mouth, headache, hypotension (including orthostatic hypotension), decreased appetite, injection site redness, burning, or pain Rare... 

Paradoxical CNS excitement and restlessness, slurred speech, tremor, dry mouth, diarrhea, nocturia, impotence, bradycardia, hypotension, syncope... 

Can antidepressants such as tricyclics or buproprion augment the effect of stimulants on nondepressed children with ADHD Randomized controlled trials have yet to address this question. Nonetheless, such combinations are common in clinical practice. One case report showed leukopenia in a child treated with a combination of MPH and tricyclics for 4 months, although the doses were not specified (Burke et ah, 1995). Another case report indicated that obsessive-compulsive symptoms developed secondary to the combination of MPH and tricyclics (Pataki et ah, 1993). On a cautionary note, MPH has been found to interact with guanethidine to produce paradoxical hypotension. Patients on monoamine oxidose (MAO) inhibitors are likely to develop hypertensive crises if given a stimulant. 

Antipsychotics block aj-adrenergic receptors, which can result in orthostatic hypotension and dizziness. Administration of epinephrine, which stimulates both a- and P-adrenergic receptors, will result in a paradoxical decrease in blood pressure because of the stimulation of P-adrenergic receptors in the presence of aj-adrenergic receptor blockade. 

Tranquilizer, sedation, antiemetic Dose Adults. N Initial max 2.5 mg IV/EM, may repeat 1.25 mg based on response Premed 2.5-10 mg IV, 30-60 min preop Peds. Premed 0.1-0.15 mg/kg/dose Caution [C, ] Contra Component sensitivity Disp Inj SE Drowsiness, i BP, occasional tach extrapyramidal Rxns, T QT interval, arrhythmias Interactions T Effects W/ CNS depressants, fentanyl, EtOH T hypotension W/ antihypertensives, nitrates EMS Monitor ECG, may T QT interval epi may cause paradoxical hypotension, do not use fentanyl may cause HTN, do not use if possible use caution w/ analgesics and opioids may T CNS depression monitor for S/Sxs of extrapyramidal Rxns which can be treated w/ Benadryl concurrent EtOH use can T CNS depression OD May cause T of nl SEs symptomatic and supportive... 

Infusion related hypotension (administer slowly), somnolence, CNS depression, ataxia. Hypersensitivity reactions. Paradoxic excitation. 

Paradoxically, elevated levels of E and NE can cause a reduction in plasma volume that can lead to hemoconcen-tration and poor tissue perfusion however, the mechanism of this effect is not known. This is said to be the cause of orthostatic hypotension in untreated patients with pheochro-mocytoma, a tumor of chromaffin tissue that produces excessive amounts of NE most of these patients have reduced plasma volume but exhibit hypertension while in the reclining position. 

Hypotension, heart block, heart failure, bronchospasm, nausea, scalp tingling, paradoxical pressor response may not be effective in patients receiving alpha- or beta-antagonists... 

Hypotension, tachycardia, headache, angina, paradoxical pressor response... 

Occasional Confusion amnesia disinhibition paradoxical excitement depression dizziness witiidrawal symptoms, including convulsions, on abrupt discontinuance (witiidrawal may be especially difficult with alprazolam) rebound insomnia or excitement Rare Hypotension blood dyscrasias jaundice allergic reactions paradoxical rage reactions stuttering with alprazolam BUPROPION, Anxiety agitation insomnia tremor anorexia BUSPIRONE, Dizziness headache nausea paresthesias diarrhea CHLORDIAZEPOXIDE, see Benzodiazepines CHLORPROMAZINE, see Phenothiazines, aliphatic CHLORPROTHIXENE, similar to Phenothiazines CLOMIPRAMINE, see Tricyclic antidepressants CLORAZEPATE, see Benzodiazepines CLOZAPINE... 

---