Nifedipine for the relief of renal colic: a double-blind, placebo-controlled clinical trial

Current and emerging pharmacological targets for medical expulsive therapy

The primary goals of medical expulsive therapy are to increase the rate of stone expulsion along the ureter to avoid ureteral obstruction and reduce ureteral colic and thus avoid the need for surgical and more invasive interventions. This review focussed on the findings from in vivo and in vitro animal and human studies that have investigated the pharmacological mechanisms controlling ureteral motility and their translation to current and potentially new clinically used drugs for increasing the rate of stone expulsion along the ureter. The complicated contractility profile of the ureter, which alters with age, tissue segment region, orientation and species contributes to the difficulty of interpreting studies on ureteral pharmacology, which translates to the complexity of discovering ideal drug targets for medical expulsive therapy. Nevertheless, the current drug classes clinically used for patients with stone lodgement include α₁ -adrenoceptor antagonists, calcium channel blockers and NSAIDS, whilst there are promising targets for drug development that require further clinical investigations including the phosphodiesterase type 5 enzyme, β-adrenoceptors and 5-HT receptors.

Nonsteroidal anti-inflammatory drugs (NSAIDs) and non-opioids for acute renal colic

BACKGROUND

Renal colic is acute pain caused by urinary stones. The prevalence of urinary stones is between 10% and 15% in the United States, making renal colic one of the common reasons for urgent urological care. The pain is usually severe and the first step in the management is adequate analgesia. Many different classes of medications have been used in this regard including non-steroidal anti-inflammatory drugs and narcotics.

OBJECTIVES

The aim of this review was to assess benefits and harms of different NSAIDs and non-opioids in the treatment of adult patients with acute renal colic and if possible to determine which medication (or class of medications) are more appropriate for this purpose. Clinically relevant outcomes such as efficacy of pain relief, time to pain relief, recurrence of pain, need for rescue medication and side effects were explored.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register (to 27 November 2014) through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Only randomised or quasi randomised studies were included. Other inclusion criteria included adult patients with a clinical diagnosis of renal colic due to urolithiasis, at least one treatment arm included a non-narcotic analgesic compared to placebo or another non-narcotic drug, and reporting of pain outcome or medication adverse effect. Patient-rated pain by a validated tool, time to relief, need for rescue medication and pain recurrence constituted the outcomes of interest. Any adverse effects (minor or major) reported in the studies were included.

DATA COLLECTION AND ANALYSIS

Abstracts were reviewed by at least two authors independently. Papers meeting the inclusion criteria were fully reviewed and relevant data were recorded in a standardized Cochrane Renal Group data collection form. For dichotomous outcomes relative risks and 95% confidence intervals were calculated. For continuous outcomes the weighted mean difference was estimated. Both fixed and random models were used for meta-analysis. We assessed the analgesic effects using four different outcome variables: patient-reported pain relief using a visual analogue scale (VAS); proportion of patients with at least 50% reduction in pain; need for rescue medication; and pain recurrence. Heterogeneity was assessed using the I² test.

MAIN RESULTS

A total of 50 studies (5734 participants) were included in this review and 37 studies (4483 participants) contributed to our meta-analyses. Selection bias was low in 34% of the studies or unclear in 66%; performance bias was low in 74%, high in 14% and unclear in 12%; attrition bias was low in 82% and high in 18%; selective reporting bias low in 92% of the studies; and other biases (industry funding) was high in 4%, unclear in 18% and low in 78%.Patient-reported pain (VAS) results varied widely with high heterogeneity observed. For those comparisons which could be pooled we observed the following: NSAIDs significantly reduced pain compared to antispasmodics (5 studies, 303 participants: MD -12.97, 95% CI -21.80 to - 4.14; I² = 74%) and combination therapy of NSAIDs plus antispasmodics was significantly more effective in pain control than NSAID alone (2 studies, 310 participants: MD -1.99, 95% CI -2.58 to -1.40; I² = 0%).NSAIDs were significantly more effective than placebo in reducing pain by 50% within the first hour (3 studies, 197 participants: RR 2.28, 95% CI 1.47 to 3.51; I² = 15%). Indomethacin was found to be less effective than other NSAIDs (4 studies, 412 participants: RR 1.27, 95% CI 1.01 to 1.60; I² = 55%). NSAIDs were significantly more effective than hyoscine in pain reduction (5 comparisons, 196 participants: RR 2.44, 95% CI 1.61 to 3.70; I² = 28%). The combination of NSAIDs and antispasmodics was not superior to NSAIDs only (9 comparisons, 906 participants: RR 1.00, 95% CI 0.89 to 1.13; I² = 59%). The results were mixed when NSAIDs were compared to other non-opioid medications.When the need for rescue medication was evaluated, Patients receiving NSAIDs were significantly less likely to require rescue medicine than those receiving placebo (4 comparisons, 180 participants: RR 0.35, 95% CI 0.20 to 0.60; I² = 24%) and NSAIDs were more effective than antispasmodics (4 studies, 299 participants: RR 0.34, 95% CI 0.14 to 0.84; I² = 65%). Combination of NSAIDs and antispasmodics was not superior to NSAIDs (7 comparisons, 589 participants: RR 0.99, 95% CI 0.62 to 1.57; I² = 10%). Indomethacin was less effective than other NSAIDs (4 studies, 517 participants: RR 1.36, 95% CI 0.96 to 1.94; I² = 14%) except for lysine acetyl salicylate (RR 0.15, 95% CI 0.04 to 0.65).Pain recurrence was reported by only three studies which could not be pooled: a higher proportion of patients treated with 75 mg diclofenac (IM) showed pain recurrence in the first 24 hours of follow-up compared to those treated with 40 mg piroxicam (IM) (60 participants: RR 0.05, 95% CI 0.00 to 0.81); no significant difference in pain recurrence at 72 hours was observed between piroxicam plus phloroglucinol and piroxicam plus placebo groups (253 participants: RR 2.52, 95% CI 0.15 to12.75); and there was no significant difference in pain recurrence within 72 hours of discharge between IM piroxicam and IV paracetamol (82 participants: RR 1.00, 95% CI 0.65 to 1.54).Side effects were presented inconsistently, but no major events were reported.

AUTHORS' CONCLUSIONS

Although due to variability in studies (inclusion criteria, outcome variables and interventions) and the evidence is not of highest quality, we still believe that NSAIDs are an effective treatment for renal colic when compared to placebo or antispasmodics. The addition of antispasmodics to NSAIDS does not result in better pain control. Data on other types of non-opioid, non-NSAID medication was scarce.Major adverse effects are not reported in the literature for the use of NSAIDs for treatment of renal colic.

[Ureter drugs]

Many improvements have been made recently in the field of the ureteral smooth muscle pharmacology. After a brief summary on physiological basis, we review what is known about effects on ureter of different drugs class. In a second part, we review clinical applications for renal colic analgesia, calculi expulsive medical therapy, ESWL adjuvant treatment and preoperative treatment before retrograde access. There are now sufficient data on NSAID and alpha-blockers. beta-agonists, especially for beta3 selective ones, and topical drugs before retrograde access are interesting and should be further evaluated.

Pharmacological management of renal colic in the older patient

Renal colic affects up to 12% of the population. Initial management of most patients is expectant. Acute symptom management of renal colic is best accomplished with a combination of parenteral opioids and NSAIDs. The elderly patient with a kidney stone should be screened for contraindications to NSAID therapy, such as renal failure or previous peptic ulcer disease. Use of parenteral opioids is often necessary during the acute setting, and downward-adjusted doses and monitoring are necessary to prevent associated confusion and respiratory depression. Novel therapy with desmopressin may also be effective for symptom control at the initial presentation, without the adverse effects of opioids or NSAIDs. However, use of desmopressin in the elderly must be undertaken cautiously, given the potential adverse effects of this agent. Many small, distal ureteral stones are treated initially with watchful waiting for the first 2-4 weeks after presentation. The patient should have effective, non-parenteral analgesics for use at home. Included in these agents are oral or suppository NSAIDs and oral opioids. Medical expulsion therapy with alpha-adrenoceptor antagonists or calcium channel antagonists is efficacious. alpha-Adrenoceptor antagonists such as the alpha(1A/)(1)(D)-selective tamsulosin are well tolerated in the elderly and increase the rate of spontaneous stone passage by approximately 50% for small distal stones. These agents also appear to decrease the severity of renal colic. Corticosteroids and calcium channel antagonists are also effective but their use in the elderly is not recommended as first-line therapy.

A systematic review of medical therapy to facilitate passage of ureteral calculi

STUDY OBJECTIVE

Acute renal colic is a common presenting complaint to the emergency department. Recently, medical expulsive therapy using alpha-antagonists or calcium channel blockers has been shown to augment stone passage rates of moderately sized, distal, ureteral stones. Herein is a systematic evaluation of the use of medical expulsive therapy to facilitate ureteral stone expulsion.

METHODS

We searched the databases of MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. Additional sources included key urologic journals and bibliographies of selected articles. We included studies that incorporated a randomized or controlled clinical trial design, patients older than 18 years, treatment in which an alpha-antagonist or calcium channel blocker was compared to a standard therapy group, and studies that reported stone expulsion rates. A random effects model was used to obtain summary risk ratios (RRs) and 95% confidence intervals (CIs) for stone expulsion rate.

RESULTS

A pooled analysis of 16 studies using an alpha-antagonist and 9 studies using a calcium channel blocker suggested that the addition of these agents compared to standard therapy significantly improved spontaneous stone expulsion (alpha-antagonist RR 1.59; 95% CI 1.44 to 1.75; number needed to treat 3.3 [95% CI 2.1 to 4.5]; calcium channel blocker RR 1.50; 95% CI 1.34 to 1.68; number needed to treat 3.9 [95% CI 3.2 to 4.6]) in patients with distal ureteral stones. Subgroup analysis of trials using concomitant medications (ie, low-dose steroids, antibiotics, and elimination of trials using an anticholinergic agent) yielded a similar improvement in stone expulsion rate. Adverse effects were noted in 4% of patients receiving alpha-antagonist and in 15.2% of patients receiving calcium channel blockers.

CONCLUSION

Our results suggest that "medical expulsive therapy," using either alpha-antagonists or calcium channel blockers, augments the stone expulsion rate compared to standard therapy for moderately sized distal ureteral stones.

Medical Therapy of Urolithiasis

Nephrolithiasis treatment has become easier and less invasive with the development of extracorporeal shockwave lithotripsy (SWL) and endourologic techniques. However, medical therapy represents a well-established and complementary approach that can improve the efficacy of SWL and endourology. During recent decades, pharmacologic intervention has become more effective in stone disease: drugs can control the pain of renal colic, interfere at various levels in lithogenesis, and contribute to the expulsion of stones. It is well known that lithogenesis is a multifactorial process influenced by environmental-nutritional factors (low urinary volume, diet rich in animal protein, etc) and metabolic alterations; i.e., hypercalciuria, hyperuricosuria, and deficiency of stone-inhibiting factors (citrate, magnesium, glycosaminoglycans [GAGs]). Specific drugs such as citrate, allopurinol, and thiazide represent highly effective treatments for the promoting factors. Furthermore, recent findings suggest an interesting role for a phytotherapeutic agent, Phillantus niruri, and its inhibitory action on calcium oxalate crystallization related to the higher incorporation of GAGs into the calculi. Another step forward in medical management of stone disease is expulsive therapy. Many studies have proven the efficacy of medical expulsive therapy with nifedipine and alpha-blockers: their specific action on ureteral smooth muscle in association with anti-edema drugs accounts for their efficacy in expelling ureteral stones. In this paper, we provide an update on the medical treatment of stone disease, focusing our attention on what is known and what is new in renal colic and litholithic and expulsive medical therapy.

Is there a role for antimuscarinics in renal colic? A randomized controlled trial

PURPOSE

We determined whether the addition of hyoscine butylbromide (Buscopan) reduces the amount of opioid analgesia required and the need for ongoing opioid analgesia in acute renal colic.

MATERIALS AND METHODS

Patients with a clinical diagnosis of acute renal colic were prospectively randomized to receive Buscopan or placebo in addition to morphine and intravenous fluids, with or without indomethacin. Observations and pain scores were recorded 15 every minutes during the first hour then hourly thereafter. Morphine was administered in 2.5 mg increments until pain relief was achieved. Recordings were ceased at 4 hours or on discharge from the emergency department, whichever occurred first. The diagnosis of renal colic was confirmed by computerized tomography. The dose of morphine (mg/kg) and the proportion of patients who required further morphine were compared between the 2 groups.

RESULTS

Of the 192 patients randomized, data were available for 178 on an intent to treat basis. A total of 85 patients received Buscopan while 93 received placebo in addition to standard therapy. Patients in the Buscopan group required a median of 0.12 mg/kg of morphine while those in the placebo group received a median of 0.11 mg/kg, and this difference was not significant (p =0.4). There was also no significant difference in the proportion of patients who required additional morphine, 33% in the Buscopan group and 38% in the placebo group (p =0.5). Subgroup analysis of the 138 patients with a confirmed stone also showed no difference between the groups.

CONCLUSIONS

There is no evidence that Buscopan reduces opioid requirements or the need for ongoing opioid analgesia in acute renal colic.

Amitriptyline eliminates calculi through urinary tract smooth muscle relaxation

BACKGROUND

We investigated the effects of amitriptyline in the urinary tract smooth muscle and urolithiasis.

METHODS

Cats presenting with obstructive acute renal failure (ARF) received amitriptyline, and renal function and survival rates were analyzed. Isometric contractions and membrane potentials of rat, pig, or human isolated urinary tract smooth muscle were recorded in the presence or absence of amitriptyline.

RESULTS

Twenty cats with obstructive ARF caused by urethral plugs received amitriptyline. In all cases, plugs were completely eliminated, and renal function returned to normal, with a 100% survival rate in the follow-up. Amitriptyline produced potent relaxations in rat urethral strips, accompanied by significant reductions in urethral ring membrane potential. This effect was prevented by pretreatment of urethral rings with 4-aminopyridine (4-AP), a voltage-dependent potassium channel blocker. Amitriptyline abolished in a reversible manner acetylcholine-, bradykinin-, and KCl-induced contractions in rat isolated bladder, and this effect was also prevented by 4-AP. Of interest, spontaneous and KCl-induced contractions of pig and human isolated ureter were also blocked by amitriptyline.

CONCLUSION

Our results indicate that amitriptyline is an effective and potent relaxant of urinary tract smooth muscle and this effect is mediated by opening of voltage dependent-potassium channels. We suggest that amitriptyline administration may help to promote elimination of urinary calculi.

Intensive medical management of ureteral calculi

OBJECTIVES

To compare two treatment regimens in patients with ureteral calculi. One regimen (control arm) used routine drugs, and the second regimen (treatment arm) used the same routine drugs plus uncommonly used drugs.

METHODS

Between February and October 1998, 70 consecutive patients were evaluated for symptomatic ureteral calculi. Thirty-five patients were randomized to a control arm and received ketorolac, oxycodone, and acetaminophen combination tablets and prochlorperazine suppositories. Thirty-five patients were randomized to the treatment arm and received the same medications plus nifedipine XL, prednisone, and trimethoprim/sulfa combination tablets and plain acetaminophen. Stone passage rates, work days lost, emergency room visits, surgical interventions, and possible side effects of the drugs were recorded.

RESULTS

The treatment arm (addition of nifedipine XL, prednisone, trimethoprim/sulfa, and plain acetaminophen) had higher (86% versus 56%) stone passage rates and fewer lost work days (mean 1.76 versus 4.9), emergency room visits (1 versus 4), and surgical interventions (2 versus 15). Both arms exhibited similar potential drug side effects.

CONCLUSIONS

The addition of a calcium channel blocking agent, steroids, antibiotics, and more acetaminophen effected a higher stone passage rate and fewer lost work days, emergency room visits, and surgical interventions.

Nifedipine and methylprednisolone in facilitating ureteral stone passage: a randomized, double-blind, placebo-controlled study

Expulsive medical therapy of ureteral stones is not well established. To test the efficacy of a calcium antagonist (nifedipine) associated with a corticosteroid (methylprednisolone) in facilitating ureteral stone passage, we studied 86 patients with a unilateral ureteral radiopaque stone not larger than 15 mm. in maximum diameter, confirmed in each case by drop excretory urography. Patients were randomly treated for a maximum of 45 days under double-blind conditions with 16 mg. methylprednisolone plus 40 mg. nifedipine daily (group 1-13 women and 30 men, mean age 45 +/- 14 years, standard deviation) and with 16 mg. methylprednisolone plus placebo daily (group 2-18 women and 25 men, mean age 43 +/- 14 years). All patients also received 2 l. of low mineral content water daily. The average maximum diameter of the stones was 6.7 +/- 3.0 mm. in group 1 and 6.8 +/- 2.9 mm. in group 2 (not significant). Partial ureteral obstruction was present in approximately half of the patients in both groups. Four patients in group 1 and 6 in group 2 dropped out of the study. In group 1, 34 patients had successful results (stone passage without surgical manipulation) and 5 failed (success rate 87%), compared to 24 and 13, respectively, in group 2 (success rate 65%). This difference was significant (p = 0.021, Fisher's exact test). No difference was present in the maximum stone diameter among the successful cases in groups 1 and 2 (6.4 +/- 2.8 and 5.3 +/- 2.2 mm., respectively, not significant). In both groups the maximum diameter of the stone was larger in the failed than in the successful cases (group 1-10.4 +/- 3.0 versus 6.4 +/- 2.8 mm., p = 0.005, and group 2-9.3 +/- 2.5 versus 5.3 +/- 2.2 mm., p = 0.0001). In group 1 the mean interval for stone passage in the successful cases was 11.2 +/- 7.5 days, compared to 16.4 +/- 11.0 days in group 2 (p = 0.036, Student's t test). We conclude that nifedipine associated with methylprednisolone is effective in facilitating ureteral stone passage.

[Pain therapy in acute renal colic.]

The severe pain of a renal colic is an emergency and requires a fast and sufficient analgesic therapy with few side-effects. The release of the ureteral obstruction is secondary to this initial treatment. Inhibition of prostaglandin synthesis directly interferes with the mechanism of renal colic pain. Dipyrone, indomethacin and diclofenac are the drugs of choice. They should be administered intravenously if possible. Narcotic agents and their derivatives are the second choice. Spasmolytic agents are unnecessary in the treatment of renal colic.