China
Africa
Explore chapters and articles related to this topic
Adrenergic Agonists
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Midodrine is used as a prodrug with α1 receptor agonist activity. Active metabolite formed is desglymidodrine. Its duration of activity is about 4–6 h and the half-life is about 3 h (Katzung et al., 2014). Midodrine activates α1 receptors causing vasoconstriction resulting in a rise in the diastolic and systolic blood pressure while standing, sitting, and in supine positions, hence used for treating postural hypotension, hypotension caused by infections in infants, psychotropic agents induced hypotension, hypotension in persons having renal dialysis, and autonomic insufficiency (Golan, 2012; Brunton et al., 2011). It is absorbed rapidly after administering orally. The peak concentration is achieved approximately 1 h following the administration. Metabolism occurs in the liver and in other tissues (Brunton et al., 2011; Stevens et al., 2008; Tripathi, 2014).
Answers
Published in Andrew Schofield, Paul Schofield, The Complete SAQ Study Guide, 2019
Andrew Schofield, Paul Schofield
Falls are common in the elderly, and the number of causes is vast. Arthritis, reduced cognition, polypharmacy, reduced visual input, reduced muscle strength, reduced proprioception and an increased reaction time all contribute to the increased risk of falling. As a junior doctor, you will be asked to assess numerous patients who have been admitted with falls, or who have fallen during their admission. It is important to take a full history to establish the mechanism of the fall, whether consciousness was lost, what injuries have been sustained, etc. A collateral history from someone who witnessed the fall can be extremely helpful. Postural hypotension is a fall in blood pressure on standing. Antihypertensives are commonly responsible, and stopping them often resolves the problem. However, in many cases no cause will be found. Non-pharmacological measures should be tried first, such as full-length compression hosiery, tilting the bed so it is more upright and increasing salt in the diet. Fludrocortisone is a synthetic mineralocorticoid and acts to increase the intravascular volume, hence raising the blood pressure. Midodrine is a locally acting vascular bed vasoconstrictor, and is contraindicated in those with peripheral vascular disease and coronary artery disease.
Pharmacological Treatment of Orthostatic Hypotension
Published in David Robertson, Italo Biaggioni, Disorders of the Autonomic Nervous System, 2019
Midodrine, a longer-acting α-agonist (duration of action 4-6 h), has been used with success at 7.5-30 mg/day in divided doses (Schirger et al., 1981). One double-blind study suggested a pressor role for midodrine in mildly impaired patients, but this agent was depressor in the more severely impaired patients, presumably by producing volume depletion (Kaufmann et al., 1988). It does not cross the blood-brain barrier and this lessens the incidence of central stimulating side effects.
Clinical trial of home blood pressure monitoring following midodrine administration in hypotensive individuals with spinal cord injury
Published in The Journal of Spinal Cord Medicine, 2023
Jill M. Wecht, Joseph P. Weir, Caitlyn G. Katzelnick, Trevor A. Dyson-Hudson, William A. Bauman, Steven C. Kirshblum
Each week, participants were asked questions related to the symptoms of AD and OH to capture both the frequency and intensity of symptoms over the preceding 7-day period. The symptoms included headache, pounding in the ears, tingling or itching of the scalp, goosebumps, chills, blurry vision, and dizziness. Additionally, participants were asked questions related to known adverse effects of midodrine including constipation, muscle spasms, urinary urge or increased lower abdominal pressure. The participants were asked: “how often did you experience this symptom?” which were rated on the following scale: 0-never, 1-occasionally, 2-sometimes, 3-often, or 4-always, and then: “on a scale of 0–100, how intense was the symptom?” 0 = not at all, 100 = very intense. The frequency and intensity of symptoms reported over each 30-day period were compared weekly under the conditions of midodrine versus placebo.
Renal and Hepatic Disease: Cnidoscolus aconitifolius as Diet Therapy Proposal for Prevention and Treatment
Published in Journal of the American College of Nutrition, 2021
Maria Lilibeth Manzanilla Valdez, Maira Rubi Segura Campos
The treatment with vasoconstrictors and albumin is one of the first options to choose. The goal of treatment is to produce vasoconstriction in the splenic vascular bed and reduce hypovolemia.Alpha adrenergic agonists: norepinephrine, midrodine. Norepinephrine is a catecholamine that acts on adrenergic receptors. Midodrine acts as a selective agonist of peripheral alpha-1 receptors, generating vasoconstriction and increased blood pressure (55).Somastostin analogues: Octreotide, an octapeptide analogous to somastatin with potent vasoconstrictor action on the splenic vasculature. It acts as an inhibitor of the secretion of peptides synthesized by the gastro-endocrine-pancreatic endocrine system, having the effect of decreasing splenic blood flow (55).Vasopressin analogues: ornipressin, terlipressin. Ornipressin has shown benefits in SHR, but due to its ischemic effects such as arrhythmias, myocardial ischemia and cutaneous necrosis, it has been abandoned. Terlipressin is a synthetic derivative of vasopressin, which has a dominant action on V1 receptors, with a potent vasoconstrictor effect. The administration of volume expanders such as albumin improve the effect of vasoconstrictors (54).
Terlipressin for the treatment of hepatorenal syndrome: an overview of current evidence
Published in Current Medical Research and Opinion, 2019
Jingqiao Zhang, Martin Rössle, Xinmiao Zhou, Jiao Deng, Lu Liu, Xingshun Qi
One randomized trial compared the effect of terlipressin plus albumin versus midodrine, octreotide plus albumin for renal function improvement in HRS I and HRS II patients27. Quality of evidence was very low for this study (Supplementary Table 4). Terlipressin was administered by continuous intravenous infusion at an initial dose of 3 mg/day. If the serum creatinine level did not decrease within 2 days by 25% or more, the dose of terlipressin was increased to 12 mg/day. Midodrine was given orally at an initial dose of 7.5 mg every 8 hours to a maximum of 12.5 mg every 8 hours. Octreotide was subcutaneously given at an initial dose of 100 µg every 8 hours to a maximum of 200 µg. Both groups received albumin at a dosage of 1 g/kg body weight at day one followed by 20–40 g/day thereafter. The rate of renal recovery was much higher in the terlipressin group compared with the midodrine/dopamine group (70.4% versus 28.6%, p = .01). Notably, one serious adverse event was stroke in the terlipressin group and it was lethal.