In pregnancy, enalapril may result in damage to the fetuss kidneys and resulting oligohydramnios (not enough amniotic fluid). Enalapril is secreted in breast milk and is not recommended for use while breastfeeding. Side effects
The most common side effects of enalapril include increased serum creatinine (20%), dizziness (2–8%), low blood pressure (1–7%), syncope (2%), and dry cough (1–2%). The most serious common adverse event is angioedema (swelling) (0.68%) which often affects the face and lips, endangering the patients airway. Angioedema can occur at any point during treatment with enalapril, but is most common after the first few doses. Angioedema and fatality therefrom are reportedly higher among black people. Agranulocytosis has been observed with Enalapril. Mechanism of action
Normally, angiotensin I is converted to angiotensin II by an angiotensin-converting enzyme (ACE). Angiotensin II constricts blood vessels, increasing blood pressure. Enalaprilat, the active metabolite of enalapril, inhibits ACE. Inhibition of ACE decreases levels of angiotensin II, leading to less vasoconstriction and decreased blood pressure. Pharmacokinetics
Pharmacokinetic data of enalapril:
Onset of action: about  1 hour
Peak effect: 4–6 hours
Duration: 12–24 hours
Absorption: ~60%
Metabolism: prodrug, undergoes biotransformation to enalaprilat

History
Squibb developed the first ACE inhibitor, captopril, but it had adverse effects such as a metallic taste (which, as it turned out, was due to the sulfhydryl group). Merck & Co. developed enalapril as a competing prodrug. : 12–13 Enalaprilat was developed partly to overcome these limitations of captopril. The sulfhydryl moiety was replaced by a carboxylate moiety, but additional modifications were required in its structure-based design to achieve a potency similar to captopril.
Flavoxate is an anticholinergic with antimuscarinic effects. Its muscle relaxant properties may be due to a direct action on the smooth muscle rather than by antagonizing muscarinic receptors. Clinical uses
Flavoxate is used to treat urinary bladder spasms. It is available under the trade name Urispas (Paladin)(india), Genurin (by Recordati, Italy) in Italy and KSA, Uritac by El Saad company in Syria,  under the name Bladderon by Nippon Shinyaku of Japan, or Bladuril in Chile, Utispas ( Apex Pharma) in Nepal. Flavoxate is indicated for symptomatic relief of interstitial cystitis, dysuria, urgency, nocturia, suprapubic pain, frequency and incontinence as may occur in cystitis, prostatitis, urethritis, urethrocystitis/urethrotrigonitis. Side effects
Flavoxate is generally well tolerated, but can potentially cause vomiting, upset stomach, dry mouth or throat, blurred vision, eye pain, and increased sensitivity of the eyes to light. Contraindications
Flavoxate is contraindicated in patients who have any of the following obstructive conditions: pyloric or duodenal obstruction, obstructive intestinal lesions or ileus, achalasia, gastrointestinal hemorrhage and obstructive uropathies of the lower urinary tract. References


== Further reading ==