II. History
- Listed for historical reasons
- No longer available in the United States as of 2013
- Was the only FDA approved drug for Preterm LaborTocolysis
III. Indications
IV. Contraindications
- Absolute contraindications
- Maternal cardiac disease
- Pregnancy Induced Hypertension (PIH)
- Uncontrolled Diabetes Mellitus
- Hyperthyroidism
- Hypovolemia
- Relative contraindications
- Diabetes Mellitus
- Chronic Hypertension
- Migraine Headache
- Resting Tachycardia
- Fever
V. Mechanism
- Phenethylamine derivative with beta-2 Adrenergic Agonist activity
- Results in Smooth Muscle relaxation (esp. myometrium) and used as a Tocolytic agent
- Similar activity to Terbutaline, with intracellular cAMP mediated effects
VI. Dosing: Intravenous
- Preparation
- Mix Ritodrine 150 mg in 500 ml D5W (0.3 mg/ml)
- Results in drip of 50 mcg/minute = 10 ml/hour
- Start: 50 mcg per minute
- Increase by 50 mcg/minute every 10 minutes until
- Contractions cease
- Adverse effects limit use
- Maximum dosage: 350 mcg per minute
- After contractions stop
- Reduce by 50 mcg every 30 minutes
- Titrate dose to lowest effective Tocolytic dose
VII. Dosing: Oral (Not effective)
- Start: 10 mg PO every 2 hours for 24 hours
- Next: 10 to 20 mg PO every 4 to 6 hours as needed
VIII. Adverse Effects
- Cardiovascular effects (more significant than with Terbutaline)
- Palpitations
- Anxiety
- Shortness of Breath
- Pulmonary Edema
- Headache
- Nausea or Vomiting
- Hypokalemia
- Hyperglycemia
- Cardiac ischemia
IX. Monitoring
- Baseline testing to consider
- Close monitoring
- Blood Pressure for Hypertension
- Pulse for maternal Tachycardia over 100
- Follow Urine Output
- Lung Exam for signs of Pulmonary Edema
- Follow Serum Glucose and Serum Potassium
- Consider fluid restriction <2400 cc per day
X. Efficacy
- Not shown to be more effective than Placebo
- Does not reduce perinatal mortality or delay labor
- (1992) N Engl J Med 327:308-12 [PubMed]
XI. References
- Gabbe (2002) Obstetrics p. 787-91
- Roberts (1998) Procedures Emergency Medicine p. 993-5
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Definition (MSH) | An adrenergic beta-2 agonist used to control PREMATURE LABOR. |
Definition (NCI) | A phenethylamine derivative with tocolytic activity. Ritodrine binds to and activates beta-2 adrenergic receptors of myometrial cells in the uterus, which decreases the intensity and frequency of uterine contractions. Specifically, ritodrine probably activates adenyl cyclase, thereby increasing production of cyclic adenosine monophosphate (cAMP), which in turn enhances the efflux of calcium from vascular smooth muscle cells. A lack of intracellular calcium prevents uterine myometrial contractions. In addition, this agent may directly inactivate myosin light chain kinase, a critical enzyme necessary for the initiation of muscle contractions. |
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D012312 |
SnomedCT | 372893009, 89785009 |
English | Ritodrine, Benzenemethanol, 4-hydroxy-alpha-(1-((2-(4-hydroxyphenyl)ethyl)amino)ethyl)-, (R*,S*)-, ritodrine, Ritodrine [Chemical/Ingredient], Ritodrine (product), Ritodrine (substance), RITODRINE |
Swedish | Ritodrin |
Czech | ritodrin |
Finnish | Ritodriini |
Russian | RITODRIN, РИТОДРИН |
Japanese | ウテメック, ウテロトップ, ウルペティック, リトドール, リトメリン, ウテメリン, リメトラーク, ピロスデン, ウテロン, 塩酸リトドリン, フレムーブ, リンドルフ, ウテメナール, ルテオニン, レキサビン, ウテゾールD, リトドリン塩酸塩, リトドリン, プレマル |
Croatian | RITODRIN |
Polish | Rytodryna |
Spanish | ritodrina (producto), ritodrina (sustancia), ritodrina, Ritodrina |
French | Ritodrine |
German | Ritodrin |
Italian | Ritodrina |
Portuguese | Ritodrina |
Ontology: Yutopar (C0043440)
Definition (CHV) | brand name of ritodrine-hydrochloride |
Definition (CHV) | brand name of ritodrine-hydrochloride |
Definition (CHV) | brand name of ritodrine-hydrochloride |
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D012312 |
English | Pre-Par [brand name], prepar, Yutopar, Pre-Par, Pre Par, Astra Brand of Ritodrine Hydrochloride, Janssen Brand of Ritodrine Hydrochloride, Solvay Brand of Ritodrine Hydrochloride, PrePar |