use strict;
use warnings;

use LWP::UserAgent;
use Tie::File;

my @pills;
tie @pills, 'Tie::File', 'pills.txt';

my $ua = LWP::UserAgent->new();

for (1..5000) {
    my $page = $ua->get('http://www.canadianmedsworld.com/item.php?id='.$_)->decoded_content;
    my ($name) = $page =~ m[<div class="item_title">(.+?)</div>];

    push @pills, $name if defined $name;
}