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British Journal of Clinical Pharmacology Jan 1982
Topics: Animals; Aromatic Amino Acid Decarboxylase Inhibitors; Blood Pressure; Humans; Hypertension; Methyldopa
PubMed: 7066154
DOI: 10.1111/j.1365-2125.1982.tb01335.x -
Journal of Toxicology. Clinical... Jul 1982A case of methyldopa overdose, confirmed by quantitative blood analysis, is presented. The clinical manifestations were coma, hypothermia, hypotension, bradycardia, and...
A case of methyldopa overdose, confirmed by quantitative blood analysis, is presented. The clinical manifestations were coma, hypothermia, hypotension, bradycardia, and dry mouth. This combination of clinical findings, previously considered characteristic of phenothiazines or tricyclic antidepressants poisoning, should also raise the suspicion of methyldopa overdose. Methyldopa is a commonly used antihypertensive agent. Surprisingly, reports on overdose are exceedingly rare [1, 2]. We have recently treated a case of methyldopa overdose in which the presenting signs resembled those of psychotropic drug poisoning.
Topics: Adult; Humans; Male; Methyldopa
PubMed: 7175995
DOI: 10.3109/15563658208992505 -
Clinical Pharmacokinetics 1982Absorption of methyldopa from the gastrointestinal tract is incomplete and variable; bioavailability after oral administration is about 25% (range 8 to 62%). The average... (Review)
Review
Absorption of methyldopa from the gastrointestinal tract is incomplete and variable; bioavailability after oral administration is about 25% (range 8 to 62%). The average time to reach maximum plasma concentration (tmax) [chemically determined] is 2 hours, when the maximum plasma concentration of active drug accounts for 50% of the radioactivity, the remainder representing various metabolites. Physicochemical determination of methyldopa shows that bi-phasic elimination occurs after both intravenous and oral administration, the half-life of the alpha-phase being 0.21 hours (range 0.16 to 0.26 hours) and of the beta-phase 1.28 hours (range 1.02 to 1.69 hours) in normal subjects. Methyldopa is less than 15% protein bound, whereas the primary metabolite, which most probably is the O-sulphate, is about 50% protein bound. The apparent volume of distribution in the central compartment is about 0.23L/kg (range 0.19 to 0.32L/kg), and the total volume of distribution (calculated as Vdarea) is about 0.60L/kg (range 0.41 to 0.72L/kg) in healthy volunteers. Acid-labile conjugates are formed after oral administration. These acid-labile conjugates, in particular the O-sulphate, are probably formed in the intestinal cells, since they are detected in very small amounts after intravenous administration. Additionally, there is a rapid formation of partly unidentified metabolites after both intravenous and oral administration. After intravenous administration the quantitatively most prominent metabolites are methyldopamine and the glucuronide of dihydroxyphenylacetone, but traces of 5 or 6 other metabolites have also been found and identified. These metabolites are probably formed in the liver, but the complete metabolic pattern is still unknown. The renal clearance of methyldopa (95 ml/min/m2) is more than 50% higher than the endogenous creatinine clearance. Renal excretion of some metabolites is slower. Extrarenal elimination accounts for about 50% of the total body clearance of the drug. Renal excretion is very low in patients with renal failure, resulting in accumulation of both active drug and, in particular, its metabolites. There is a marked accumulation of unidentified metabolites in renal failure patients, which possibly explains the strong and prolonged hypotensive action of methyldopa in these patients.
Topics: Acute Kidney Injury; Animals; Biological Availability; Half-Life; Humans; Hypertension; Intestinal Absorption; Kinetics; Methyldopa
PubMed: 7047042
DOI: 10.2165/00003088-198207030-00003 -
British Medical Journal Jan 1966
Topics: Aged; Female; Guanethidine; Humans; Hypertension; Male; Methyldopa
PubMed: 5901568
DOI: No ID Found -
CMAJ : Canadian Medical Association... Jan 1986
Topics: Aged; Bipolar Disorder; Cognition Disorders; Confusion; Drug Interactions; Female; Humans; Hypertension; Lithium; Lithium Carbonate; Methyldopa; Tremor
PubMed: 3080214
DOI: No ID Found -
JAMA May 1976
Topics: Biopsy, Needle; Chemical and Drug Induced Liver Injury; Drug Hypersensitivity; Female; Granuloma; Humans; Hypertension; Liver; Methyldopa; Middle Aged
PubMed: 946514
DOI: 10.1001/jama.235.18.2001 -
Hipertension Y Riesgo Vascular 2021Hypertension (HTN) in pregnancy is defined as systolic blood pressure ≥ 140 and/or diastolic blood pressure ≥ 90 mmHg. Based on the values, it is classified as...
Hypertension (HTN) in pregnancy is defined as systolic blood pressure ≥ 140 and/or diastolic blood pressure ≥ 90 mmHg. Based on the values, it is classified as non-severe (< 160/110 mmHg) and severe (≥ 160/110 mmHg). Before starting treatment in non-severe HTN, white- coat HTN should be ruled out. If outpatient management is possible, pharmacological initiation is suggested with sustained high values, avoiding < 120/80 mmHg. Safe drugs during pregnancy are methyldopa, labetalol, and nifedipine-retard. The use of nifedipine-XL or amlodipine can be considered with a lower level of evidence of safety. Diuretics, atenolol, and other beta-blockers for antihypertensive purposes is not recommended in this period. Renin-angiotensin-aldosterone system inhibitors are strictly contraindicated. In postpartum and breastfeeding, the same therapeutic regimen used during pregnancy can be maintained, trying early withdrawal of methyldopa. During puerperium, amlodipine and enalapril are safe, with minimal excretion in breast milk.
Topics: Amlodipine; Antihypertensive Agents; Blood Pressure; Breast Feeding; Female; Humans; Hypertension; Methyldopa; Nifedipine; Postpartum Period; Pregnancy
PubMed: 33632659
DOI: 10.1016/j.hipert.2021.01.002 -
Hypertension in Pregnancy Nov 2020to assess the maternal and fetal outcome in women with mild to moderate chronic hypertension on antihypertensive drug (methyldopa or labetalol) therapy compared to no... (Comparative Study)
Comparative Study Randomized Controlled Trial
OBJECTIVE
to assess the maternal and fetal outcome in women with mild to moderate chronic hypertension on antihypertensive drug (methyldopa or labetalol) therapy compared to no medication.
METHODS
This multicenter randomized clinical study was conducted at Menoufia University hospital, Shibin El-kom Teaching hospital at Menoufia governorate, Egypt.486 pregnant women with mild to moderate chronic hypertension were randomized into three groups; methyldopa group (n = 164), labetalol group (n = 160), and control or no medication group (n = 162) who were followed from the beginning of pregnancy till the end of puerperium to record maternal and fetal outcome.
RESULTS
There was a highly significant difference between treatment groups (methyldopa and labetalol) and control group regarding the development of maternal severe hypertension, development of preeclampsia, renal impairment, presence of ECG changes, placental abruption, and repeated admission to hospital for blood pressure control (p < 0.001) with higher occurrence in the control (no treatment) group. Neonates in the labetalol group were more prone for the development of small for gestational age (SGA), neonatal hypotension, neonatal hyperbilirubinemia, and admission to NICU than their counterparts in the methyldopa and control groups (p < 0.001). The rate of prematurity was significantly higher in the control group than the treatment groups (p < 0.05).
CONCLUSION
Treatment of mild to moderate chronic hypertension during pregnancy is beneficial in decreasing both maternal and fetal morbidity. The use of labetalol was associated with higher rates of SGA, neonatal hypotension, and neonatal hyperbilirubinemia compared to methyldopa or no medication.
Topics: Adult; Antihypertensive Agents; Blood Pressure; Female; Humans; Hypertension; Labetalol; Methyldopa; Pregnancy; Treatment Outcome; Young Adult
PubMed: 32697618
DOI: 10.1080/10641955.2020.1791902 -
JAMA May 1974
Topics: Aged; Epilepsy; Fever; Fever of Unknown Origin; Humans; Male; Methyldopa
PubMed: 4406423
DOI: 10.1001/jama.228.9.1097b -
JAMA Feb 1974
Topics: Adult; Drug Synergism; Female; Humans; Hypertension; Methyldopa; Trifluoperazine
PubMed: 4405801
DOI: 10.1001/jama.227.5.557c