Loperamide have negative effects from rebound constipation. If a suspicion exists of diarrhea associated with organisms that can penetrate the intestinal walls, such as or "Salmonella", loperamide is contraindicated as a primary treatment. Loperamide treatment is not used in symptomatic "C. difficile" infections, as it increases the risk of toxin retention and precipitation of toxic megacolon. Loperamide should be administered with caution to people with liver failure due to reduced first-pass metabolism. Additionally, caution should be used when treating people with advanced HIV, as cases of both viral and bacterial toxic megacolon have been reported. If abdominal distension is noted, therapy
Invitation to treat in the "Boots" case (described below) the offer is made by an action without any negotiations—such as presenting goods to a cashier—the offer will be presumed to be on the terms of the invitation to treat. Generally, advertisements are not offers but invitations to treat, so the person advertising is not compelled to sell. In "Partridge v Crittenden" [1968] 1 WLR 1204, a defendant who was charged with "offering for sale protected birds"—bramblefinch cocks and hens that he had advertised for sale in a newspaper—was "not" offering to sell them. Lord Parker CJ said it did not make business sense