Rectal retention

It is critically important to recognize that the treatments of hyperkalemia discussed thus far are transient, temporizing measures. They are intended to provide time to institute definitive therapy aimed at removing excess potassium from the body. Agents that increase potassium excretion from the body include sodium polystyrene sulfonate, loop diuretics, and hemodialysis or hemofiltration (used only in patients with renal failure). Sodium polystyrene sulfonate (Kayexalate , various manufacturers) can be given orally, via NG tube, or as a rectal retention enema and is dosed at 15 to 60 grams in four divided doses per day. 

Distal ulcerative colitis, proctosigmoiditis, proctitis Rectal (retention enema) 60 mi (4 g) at bedtime retained overnight for approximately 8 hr for 3-6 wk. Rectal (500-mg suppository) Twice a day. May increase to 3 times a day. Rectal (1,000-mg suppository) Once daily at bedtime. Continue therapy for 3-6 wk. 

An active substance administered as a suspension must dissolve before it can be absorbed. This may take considerable time which may be a problem due to the termination of rectal retention by defecation. For a systemic effect only a few, if any, suspension enemas are in use. For a local effect a suspension enema is frequently used, for example with mesalazine orbeclometasone. The choice between a suspension of the non-dissociated form of an active substance and a solution of the dissociated form can in the end only be based on biopharmaceutical research. 

Intestinal surface area and total blood flow to the GIT are smaller than in adults and may influence the efficiency of absorption. With regard to the use of rectal suppositories, one must keep in mind that the completeness of absorption will be a function of retention time in the rectum. Since bowel movements in... 

Acute bacterial prostatitis High fever, chills, malaise, myalgia, localized pain (perineal, rectal, sacrococcygeal), frequency, urgency, dysuria, nocturia, and retention Chronic bacterial prostatitis Voiding difficulties (frequency, urgency, dysuria), low back pain, and perineal and suprapubic discomfort Physical examination... 

Surgery for rectal cancer depends on the area involved. Although less than 33% of these patients require permanent colostomy, frequent complications include urinary retention, incontinence, impotence, andlocoregional recurrence. 

Lactulose may be given as a retention enema via a rectal balloon catheter. Do not use cleansing enemas containing soap suds or other alkaline agents. 

Portal-systemic encephalopathy PO Initially, 30-45 ml every hr. Then, 30-45 ml (20-30 g) 3-4 times a day. Adjust dose q 1-2 days to produce 2-3 soft stools a day. Rectal (as retention enema) 300 ml with 700 ml water or saline solution patient should retain 30-60 min. Repeat q4-6h. If evacuation occurs too promptly, repeat immediately. 

Rectal 100 mg/60 mL unit retention enema 90 mg/applicatorful intrarectal foam Mesalamine (5-ASA)... 

Rectal 40 mg/bottle retention enema Olsalazine (Dipentum)... 

Treatment and prophylaxis of hepatic encephalopathy Start with 30-45 ml (20 gm/30 ml) p.o. 3-4 times daily, then adjusted to achieve 2-3 soft formed stools/day or 300 ml (200 g) mixed with 700 ml of water or saline rectally as a retention enema (retain for 30-60 min) every 4-6 h. as needed... 

Solutions, suspensions, or retention enemas represent rectal dosage forms with very limited application. 

Central nervous system toxicity is unusual with vinca alkaloids, because they do not readily cross the blood-brain barrier. However, fatal myeloencephalopathy can occur a few hours after accidental intrathecal drug administration (58,59), with severe bilateral leg pain, and over the next 36 hours progressive leg weakness, urinary retention, meningism, fever, and somnolence. Other effects include absence of deep tendon and gag reflexes and disappearance of rectal tone. In spite of high-dose folinic acid rescue, patients became comatose, for example by the fourth day after injection, with loss of brain stem function a few days later. 

Dmgs administered by the rectal route in suppositories are placed in intimate contact with the rectal mucosa, which behaves as a normal lipoidal barrier. The pH in the rectal cavity lies between 7.2 and 7.4, but the rectal fluids have little buffering capacity. As with topical medication, the formulation of the suppository can have marked effects on the activity of the drug. Factors such as retention of the suppository for a sufficient duration of time in the rectal cavity also influence the outcome of therapy the size and shape of the suppository and its melting point may also determine bioavailability. 

The metabolic clearance rate of PSA follows a two-compartment model with initial half-lives of 1.2 and 0.75 hours for free PSA and total PSA and subsequent half-lives of 22 and 33 hours. Because of this relatively long half-life, 2 to 3 weeks may be necessary for the serum PSA to return to baseline levels after certain procedures, including transrectal biopsy, transrectal ultrasonography, transurethral resection of the prostate, and radical prostatectomy. Prostatitis and acute urinary retention can also elevate PSA concentration. Although the digital rectal examination has no clinically important effects on serum PSA levels in most patients, in some it may lead to a twofold elevation. 

Digital rectal exam or transrectal ultrasound to rule out prostatic enlargement. Renal function tests to rule out renal failure due to acute urinary retention. 

A mean peak plasma drug concentration of 2.6 mg/L of the "second component" with a high-performance liquid chromatography (HPLC) retention time of 26.4 min was measured in 12 healthy young men after a single oral dose of 320 mg of saw palmetto. The time to peak concentration occurred 1.5 h after administration (De Bemardi Di Valserra et al., 1994). A 640-mg rectal dose of saw palmetto extract produced a peak of 2.6 pg/rnL occurring 3 h after the dose (De Bemardi Di Valserra and Tripodi, 1994). 

---